Pool Opening Problems.

[TheGoose]

My pool got swampy on me over the end of the winter because the motor on my 1-HP Whisper-Flo crapped out and I didn't have time to fix it. I was right in the middle of a major remodel on my house when this happened.

Summary:

Pool - Approx 18K gallons 17x33 oval/rectangular 5.5' middle 4.5' ends. 2 Skimmers and main-drain connected to pump by 3-way valve.
Location -SE Texas near Houston
Pumps - 1-HP Pentair whisperflo with newly installed dual-speed motor and 3/4 HP booster for polaris 280. Dual speed not yet activated so running on high for now.
Filter - Tagelus 60D 325# Sand Filter
SWCG - Hayward Swimpure with over-sized cell for up to 40,000 gallons.

Got the new motor installed about a week ago-been running the pool almost non-stop on high speed ever since and backwashing when necessary.

Opening #'s- FC 0 pH = 8
TA = 120 CH-not tested all tested with the Taylor DPD and OTO for quick readings. I am getting low on the powder but just ordered some today.
salt = 3600 but SWCG reading 2200 when started but after adding 2 bags it's up to 3600.

I started by buying 10 gallons of 6% bleach and running the filter pump non-stop. Water changed from swampy green to blueish green in about a day or so. Added acid to adjust pH.....added 12 more gallons of 6% bleach (first reading was still low). Finally started showing chlorine, which has been up and down since.

Added acid again due to still high pH but overshot....now pH = 6.8. Added 20 mule team and 4 bottles of 10% bleach from Lowe's.

Yesterday I started the SWCG now that it is showing enough salt. Noticed immediately that the pool started foaming up.....it also made a good amount of bubbles last year...enough to make the water look cloudy at times.

Today when I checked the FC/CC and pH the reading was 0 FC and pH= 6.8 so I added the mule team.

Will re-test tonight and see where I am on pH. I was good on Alk a few days ago but I don't know what the acid did to the TA...I am told it lowers it but I'm not sure by how much. I didn't check for CC since after adding 2 dippers the solution did not turn pink. Testing with OTO shows no FC but after a few minutes it does turn pale yellow which I am also told is the CC.

I kinda know what I have to do so this thread is more about tracking my progress....but I welcome all advice/comments.

[aylad]

If your water is still bluish-green, then you need to get it back up to shock level (12-15 ppm if CYA is 0) and hold it there. You'd do your self a favor by not trying to use the SWCG to maingain shock--it will decrease your cell life substantially. It would be better to just get it there and maintain it with bleach, or possibly cal-hypo, then use the SWCG when you get it cleared up and can let the Cl drift back down again. Keep the pump and filter running, and go from there.

Honestly, if I were you I would get the pH back to the 7.2-7.6 range and then leave it alone--it's pretty easily fixed after you get the pool clear.

Let us know how it's going!

[TheGoose]

I'm running the cell on low power to supplement the shock. Sorry for the confusion. I oversized my cell by 2x so it is capable of "shocking" the pool.

Unfortunately I'm short on time and long on work. I'm gone about 14-16 hours per day and right now my schedule is about 7 days a week so I'm just unable to physically check on the pool every 2-3 hours like I should while starting it up.

Just checked the chemistry.
FC = .5
CC = 1.6-1.8 ( is that right?)
--That is the last of the powder until my new batch arrives this week. Should have sent away for it earlier. Doh!!
Still have the OTO, which seem to work "OK" for my immediate needs.

TA = 60. Figured it would be low after the acid over-dose.
pH = 7.0, maybe slightly more.
CH = 200

I know my FC is way low, but I'm out of all chlorine. I just dumped my last two jugs of 10% in the pool. That's the trouble with BBB-lugging the danged jugs and storing them. Do you think I can use chlorinated granules? Much easier to transport and store for the mean-time.

I'm also out of the CYA reagent, so no numbers there but fortunately we are rainy right now and there is very little sunlight.

==================================================

Had a lot of rain yesterday, at least a couple of inches. Mother Nature sure isn't making things easy on me.

[PoolDoc]

Do you have any idea what your CYA is? Zero? High?

You can use granular . . . but what kind you can used, depends on the CYA level.

By the way . . . right now I'm encountering one of the reasons I don't like it when folks try to be anonymous when they register. You're connecting via work, so I can tell what company you probably work for, but I can't geo-locate your IP address. And, telling me you're in Texas doesn't help much. As you Texans are fond of noting, it's a BIG state. You could be in Houston, and have everything in the world available to you, or you could be west of Killeen, in the middle of nowhere, with nothing nearby. So, I don't know what to tell you do do.

Except: if you let the chlorine get low, you'll not only stop making progress, you'll quickly revert to where you were, and essentially waste all the chemicals you've added so far.

Anyhow, if you can get one of these kits:
www.walmart.com/ip/HTH-6-Way-Test-Kit/17043668
they are a Taylor private label kit, compatible with your K-2006. Some are available in the Houston area.

Other things:

1. Turn your SWCG off, till you get the pool cleaned up. You're using up SWCG life for something they aren't very good at. You need to add LARGE amounts of chlorine by hand.
2. If you can't get anything else, get some 'guess-strips' so we can get an idea of where your CYA levels are.
3. Let me know if you have access to a Sams club
4. Go to this page -- http://www.poolforum.com/pf2/showthread.php?14994 -- and use it to order what you need, tonight. You don't have to use my links, but get the stuff.
5. If you have any calcium hypochlorite granular on hand, let me know.
6. When you are out of bleach, go ahead and use ANY form of chlorine you have, at the rate of 2# per day, till you get some test results. Adding too much stabilizer is MUCH better than not adding enough chlorine!
7. While you're at it, order borate test strips, and go ahead and plan to dose your pool to 50+ ppm borate. It will make the pool more forgiving and algae resistant.

IF you have access to Sams and IF you are willing to wait to swim, there's another option, to take the load off, without loosing ground when you can't attend to the pool.

[TheGoose]

Hey Ben thanks for the detailed answer.

I'm near Houston, but in the sticks. I do have lots and lots of trees around the pool, which are a nightmare for me, but I also enjoy the shade so it's a catch-22. They are not my trees but my neighbors. I do trim the leaves FWIW.

I already own the Taylor 2006 kit, but I'm out of the DPD powder. I already ordered it, should be here in a few days. I'm using another Taylor kit for chlorine plus a back-up OTO. The taylor kit uses two reagents for chlorine, the oto just uses one. I like the OTO better.

I'm also out of the CYA reagent, but also have some on order. We have had a lot of rain the past few days so I'm not sure if sunlight is much of a problem now. We had two inches of rain today, I actually had to drain about 2-3 inches out of the pool, it was close to overflowing!!

No Sams club, but Wal-Mart is about 15-20 minutes one-way. No big deal really, but I am already short on time. I've got about 30 empty bottles of bleach laying around the pool so that's why I'm asking about the cal hypo. I've been careful to only get the pure cal hypo and stay away from the one sold at lowes which has copper and other things in it. I also bought some 10% bleach from lowe's last week for $4.27/gallon IIRC.

Today I sent the wife for a big bag of baking soda, two lbs of stabilizer, and some regular powder cal hypo. Today my pH is back up in the 7's range, and my last TA was about 60. I need to re-test the pH again to get a better #. I have been backwashing the filter at about 28-32 lbs about every 2 days or so.

Today I really scrubbed the pool sides and floor and got everything a good rub down so the water is stirred back up.

Added some cal hypo (2 lbs) to the pool to supplement the chlorine. The level was at 5+ ppm when I got home from work at 4:30 after not adding any since last night. I really need my taylor kit refills so I can see what the exact level is.

Thanks for your advice, I have my fingers crossed that we will be able to swim by this weekend. I'm really not much for the pool in April, still too cold for my blood, even in TX.

[TheGoose]

Today's #'s.

FC = ~5+using the OTO kit. Taylor reagents not here yet.
pH = 7.2

Brought the chlorine level up before I left again with 2 lbs. of cal hypo. It is staying overnight this time also. Water is not green, but a milky white color. I scrubbed the walls again and floor.

[TheGoose]

Today's #'s

FC = 5+ (OTO kit max = 5 ppm). Best guess is between 8-10. It's not orange like I've seen in the past. Taylor DPD powder not here yet.
pH = 7.2
TA = 80-90
CH = 200

No CYA reagents yet either, should be here with the DPD powder. Seems like I'm holding chlorine OK. CYA on hand in case I need to add some.

Added 2 lbs of cal hypo for good measure. Filter pressure is medium, probably will have to back wash tomorrow. I still have about ~5 or so gallons of bleach on hand.

Added 1 bag of salt with one in reserve-salt cell was reading 2700 ppm but the last taylor test read 3600. I'm not sure how high chlorine levels affect the test. Last year the cell reading and Taylor test were dead even. We also had at least 2-5 inches of rain since my last test, one place near me reported 10" on Monday.

Waiting to see how much salt cell level comes up.

Waiting for the water to start getting clear.

Water is still very milky, visibility no more than 1 ft.

I still feel like I'm getting very low performance from my sand filter. I tried the DE powder trick and it almost immediately plugged with just a vey small amount of DE.

Scrubbing the walls daily and the floor as best I can with 0 visibility.

[TheGoose]

Measured with Taylor kit today:
FC = 6.5
CC = 1.0-1.5
As measured with .5 accuracy

pH = 7.2

For the fist time this season I was able to measue CYA. Unfortunately I ran out of column before the dot disappeared. Needless to say, CYA was added. Estimate current level at just under 30 ppm.

Suprisingly I have not had a lot of trouble keeping the FC levels up. We are starting to see lots of sun lately though after a few weeks of clouds and rain.

BTW the water is looking fairly decent now. It has a blueish tone fairly even now and seems to be getting clearer, but it is still somewhat murky.

Filter pressure was runing ~28 psi last night but I shut the pump off for a little while this morning and today the pressure is runing slightly lower at ~25. Water pressure at the jets seems pretty good so I'm gonna let it stay there for awhile.

[Watermom]

If you have a CC reading of 1.0-1.5, then you need to shock the pool back up to around 10-12. You want the CC reading to be 0.

[TheGoose]

I did shock it back up. I have been shocking at least twice a day everyday. The OTO test actually got me pretty close on FC.

Water looking much better but still murky.

[TheGoose]

FC = ~ 6-8 as measured with OTO
CC = not measured today
pH = 7.2 and seems pretty steady.
CYA not measured for a couple more days.

Water color is much better. Getting to the right shade of blue. Clarity is only slightly improved. Filter pressure running about 25 psi, base pressure about 18-20.

[TheGoose]

FC = 8.6 as measured by Taylor kit
CC = .8-1.0 using .2 ppm drops
pH = 7.0-7.2 (colors are too close for me)
TA = 80
CYA = 60

Water color is about the same...clarity is only slightly improved. Filter running about 25 psi.

[TheGoose]

Numbers from 4-22


FC = 8.0
CC = 1.0-1.5 both measured with .5 drops
pH = 7.0-7.1....might have dropped a hair. Need to get some mule team.
TA = 90

CYA not measured.
CH not measured.

Water still cloudy, filter still running 24-7.

I read somewhere that my CH could be causing the cloudiness. Something about the "Saturation Index" or something like that.

I have never measured the CH as being super high, most of my tests show it about 200, but I read that you can have false results. I have noticed that the colors change kinda funny.

Any opinions on the CH causing me problems? I will measure again tonight. I have been using cal hypo with bleach to shock the pool, but I felt that since my CH numbers were not high I was OK. I am measuring CH about once a week.

Water color is whitish blue. Just murky. I am strongly considering going back to DE, this sand filter just isn't doing a good job IMO.

[PoolDoc]

Hi Goose;

-- I edited your posts some for spacing and such so I could read through them more easily --

CH doesn't cause cloudiness unless you precipitate calcium carbonate, usually by dumping in cal hypo, bicarb, or pH up. It doesn't look like you've done so, I don't really suspect that suspended CaCO3 is the issue.

Two suggestions:

1. If you haven't already, check your filter. It sounds like your Whisperflo *may* have been big enough (25psi starting pressure!!??) to blow sand out of the filter during backwash. If you have lost sand, that will DEFINITELY cause 'failure to filter'.

2. Go ahead and get that pump running on 2-speed. Either get a timer or a DPDT motor rated toggle switch. Both the correct timer, and the correct toggle are often hard to find locally, but Amazon has them:

Intermatic T10604R Pool/Spa Control Center T106M and T104M @ Amazon (http://www.amazon.com/exec/obidos/ASIN/B0039Q7NYI/poolbooks)
Southwire 55189301 3/4-Inch 6-Feet ULTRA Whip-Pre-Assembled with Wires and Connectors @ Amazon (http://www.amazon.com/gp/product/B000BQSGEU/?tag=poolbooks)
Leviton 1282 15 Amp, 120/277 Volt, Toggle Double Throw @ Amazon (http://www.amazon.com/exec/obidos/ASIN/B0033PSG5A/poolbooks)

You'll need EITHER the timer OR the toggle, but not both. Boxes are available locally. You'll need TWO of the whips (or the local equivalent), one from your panel to the toggle/timer, and one from the toggle/timer to the pump. Your electrician will need to add a FOURTH wire to the whip that goes to the pump, to accommodate the switching. Do NOT let your electrician use metallic flex; do mandate a WIRED ground to the pump (no conduit grounds!!) no matter what the National Electric Code allows.

Also, you DO need the dual timer, because it has to be set up to START on high, and THEN switch to low. The only way to use a single timer, is if you plan to run the pump 24/7 on EITHER low or high. Even then, the dual timer is safer, since you can restart it 2x daily, to make SURE that it's primed. Pumps can lose prime during a power outage, and then start back on low, allowing the pump to run dry when it fails to prime.

Running on low speed will GREATLY increase your filter's ability to remove fine particles.

[TheGoose]

Thanks for your response. I suspect that I need to add sand, but I hate to take everything apart. It's a PITA. I really should have put some unions in last time but I didn't.

Did you see the pics I sent you a few days ago? Do you have any concerns on my set-up? I realize my back-wash line is kinda open ended. I had another pipe that ran down and away from the filter but the kids "misplaced" it for me. I will get another up ASAP and I'm also gonna install a throttle valve.

The starting pressure is normally about ~18-20 psi. I've seen it get as high as 30. I usually backwash about 28. Right now my filter is running about ~25 psi. I would have already backwashed but I'm afraid I'm losing sand everytime and also I heard that a "plugged" filter actually filters better. Also I can tell by looking at my return jets that there is plenty of flow. When the filter gets plugged you can't see the surface ripple.

Thanks for the advice on the wiring. I do all my own wiring and I do have a dedicated ground to the pump. I will make sure that the switch is grounded also. I might just get the timer instead.

[PoolDoc]

Sorry, here are the pictures:

https://lh5.googleusercontent.com/-Vp4MVOnh43w/T5XPHbp6BrI/AAAAAAAACgQ/yyKHBlrhj6I/s800/100_1986%2520web.jpg

https://lh3.googleusercontent.com/-xkAw81Y3FqM/T5XPHfmEIMI/AAAAAAAACgU/nur_pQexpUM/s800/100_1987%2520web.jpg

https://lh4.googleusercontent.com/-Ih2qZlWiCK0/T5XQ21tfUHI/AAAAAAAACgo/FE31ZLEFAz8/s800/100_1987%2520detail.jpg

https://lh6.googleusercontent.com/-Ld1hP-gcFgI/T5XRtCaotyI/AAAAAAAACg4/c-m5Dj4o4Fw/s800/100_1987%2520detail%25202.jpg

[PoolDoc]

I'm trying to work out a way to offer re-design help to members, but we're not there yet.

Right now, what I'd recommend is get to leave the plumbing alone, for the most part, but get the timer and sand taken care of. You just need 1 more union (pressure side of multi-port, near filter) in order to lift the multi-port valve. Having the messed up back wash, makes it easy for now.

You can install this check valve:


King Brothers Inc. KC-1500-S 1-1/2-Inch Slip PVC Schedule 40 Spring Check Valve, Gray @ Amazon (http://www.amazon.com/exec/obidos/ASIN/B000KKU7FS/poolbooks)

http://ecx.images-amazon.com/images/I/31UC6EMzDhL._SL500_AA300_.jpg (http://www.amazon.com/exec/obidos/ASIN/B000KKU7FS/poolbooks)

to assure positive pressure at the suction inlet of the Polaris booster. If you do, you'll need to remove the Rainbow feeder and check valve -- if that's the old 10# spring valve, it's a VERY significant energy waster! If it's a newer model with a light spring, then you won't need the check from Amazon, since the Rainbow valve will assure positive pressure at the Polaris suction.

[TheGoose]

The "housing" is new....I replaced it ~2005. The "body" of the new one cracked. I still had the original and swapped out the "new" column/body part for the original. The actual part that is in-line was replaced about '05 or so.

The "foam" in the top picture is from the SWCG when I run it higher. It definitely makes an abundance of bubbles. I have not been using it as of late per the advice on this forum.

I'm keeping the pump off tonight to see if anything will settle out of the water.

The water is much better than what you see in that picture. It is more of a whitish/blue tint now, not green BTW.

[TheGoose]

4-25 #'s
FC = 9
CC = 1.0
pH = 7.4 (added borax)
TA = 90
CH = 225
CYA = 60

Water clarity slightly better.

I ordered the dual speed timer BTW.

[TheGoose]

Today's numbers:

FC = ~5 with OTO.
pH = 7.5 I've been bringing pH up slowly.

I didn't test for anything else since those numbers don't seem to fluctuate much. I test them about 1-2 times per week.

Pool water is SLOWLY getting clear. I can just barely see the bottom of the pool in the shallow end. Water color itself looks great. The pool seems to be holding chlorine, I'm not adding much if any. I did add some water today so I'll need to re-check the numbers probably tomorrow.

Two speed timers installed and running great. the motor is really quiet on low speed.

[TheGoose]

Today's numbers-

FC = ~5 as measured with OTO.
pH - 7.2-7.4

I went swimming today. The water has a very nice color to it, all the other chemistry is in good shape...but the water is just CLOUDY.

After donning a mask and looking around underwater I am thoroughly convinced that my sand filter has failed in some way. Either the sand has been backwashed out or the valve is leaking by somewhere. There is just a lot of particles in the water. Stuff that is visible to the eye, not just real small stuff. The pump has been running 24/7 and on low since last week. I'm gonna have to take the top off again and see what the sand level is.

Going by the "grocery store" philosphy what kind of sand do I need? I usually buy the pool store stuff but I'm pretty sure that I can get some from the lumberyard that will do the trick.

By the way I used the DE trick and didn't see any results. I also did not notice any DE blowing back into the pool, so I'm at a loss on what to do next. I'm ready to go back to full on DE, I consider the sand filter experiment failed. Unless I can resolve the "problem" of sand being backwashed out.

[Watermom]

Only use filter sand. You probably will have to get it at a pool store, not the lumberyard. I'm gonna ask Ben to take a look at this thread again since it has been awhile. Maybe he can see something else to try.

[PoolDoc]

1. Backwash your filter.
2. Return to normal operation. Note clean filter pressure.
3. Add 4 - 5 quarts of DE to your skimmer. Check the pool for leakage. Check the filter for pressure increase -- it should increase.
4. Wait 24 hours -- pressure should have increased more. Let me know.

4 quarts of DE is enough to turn your sand filter into a tiny DE filter that should stop up quickly. If it does NOT stop up, and DOES not leak into the pool, THEN the problem is that some of the particles are really nasty small.

[TheGoose]

I did backwash the filter. Extensively. I backwashed for several minutes and caught samples several times. It did take a long time for the water to clear. Then I rinsed and repeat, 2-3 times. I tried to see if any sand was coming through the backwash but I never detected much, but it was hard to disceren from all the "junk" coming out either.

When I backwash my start-up pressure is normally 17-20 psi. I added about 3/4 of a 'cup' of DE to the skimmers until the pressure reached ~1-2 psi above clean pressure. Funny thing was that I came back about 15-20 minutes later and the pressure was running ~25 psi. I then shut the filter off for a few minutes and re-started, and , voila, the pressure was back about ~21-22 psi.

What bothers me is that the filter pressure will rise, over time, running normally. I now have the pump running on low speed 24/7 hoping that under low speed the sand filter can catch the stuff that normally gets through. I have the DE in the filter, but the water is still cloudy.

I need to pull the top off next and add some sand. I'm gonna put unions in on every connection. I'm gonna start with 2 bags, unless the visible level looks low enough. Then I'm gonna put a throttle valve on the BW line and pinch it down. I checked out what the flow under low speed looks like during BW and it still does about 20-30 GPM so I could just try that too.

I will try the other DE test also but I have never seen the DE blow back into the pool but I will give it a look again.

[PoolDoc]

Ok, with a Tagelus 60D, the absolute do not exceed is 47GPM. Do NOT take that sucker off low speed. You can probably even backwash on low. (Need about 40 GPM for that).

The pressure behavior you're describing is pretty typical of DE; it re-compacts under restored flow.

Also, we've got a rash of problems like yours -- probably because so many pools got 'slimed' during the exceptionally warm spring. The good side of all this (for me) is that it's giving me a widespread pattern to look at. In EVERY case, an over-pressurized sand filter has been involved. However, in one case, we're NOT seeing what we've always presumed; that the particles would be filtered by a DE or cartridge filter. In this case, the owner cleaned up (de-greened) with sand, and then switched to a cartridge, and now STILL cannot filter the cloud.

What I think may be happening is that the high rate / high flow through the sand filter is fracturing the algae particles and they are leaving the sand filter as a stream of much finer particles than when they entered. So, what I'm asking people to try, is to raise the chlorine high enough to last a couple of days, and to then turn the pump off.

My hope is, it will settle some. If it settles enough to vacuum out on waste, then we have a solution. If not, the next step is to try a floc, and then a clarifier. But it appears that these particles may not filter out in any reasonable time, except with an over-sized (low flow per sft) DE filter --- and that would be EXPENSIVE.

The way to avoid it in the future is to NEVER allow algae to be forced through a sand or cartridge filter by an oversized pump.

[TheGoose]

I know what 50 GPM looks like and I'm certain my pump does more than 50 GPM open ended. Can't really tell what the flow would be through the filter and return piping, but if you put it to waste or backwash it's at least 50-60 GPM. I wonder if there as a flowmeter built specifically for pools I can put in-line to check the flow. Also it would be handy to know when the filter is really getting plugged instead of relying on a pressure gauge.

I sized the pump /tank going by their charts-the 60D was supposed to be good up to 60 GPM and the pump was supposed to do 50-60 GPM. What I'm finding out is that I really needed the 100D (as you suggested) to handle the flow.

If I did go back to DE ( I had an old Sta-Rite Swimquip stainless DE before) which one would you recommend? My plumbing is on top, I would prefer to stay with a top mount valve so I wouldn't have to massively modify the plumbing. But I can change it if need be.

[PoolDoc]

Yes, there's a flow meter; I've always used Blue White's meters. The others were either massively expensive, or not accurate enough.

Blue-White Flowmeter for 1-1/2" PVC Pipe, Horizontal Installation (http://www.amazon.com/exec/obidos/ASIN/B00170X2LQ/poolbooks)

Blue White Flow Meter manual (http://www.bluwhite.com/Products/VariableArea/F-300/071_TECH_F300_IPS%20Pipe.pdf)

Regarding filters -- a sand filter will do fine, if you keep the flow in the correct range. I'm realizing I've never personally seen the sort of problems everyone is having, because whenever I took over a pool, I'd whine and fuss until I could replace the pump or the filters, OR I'd surreptitiously throttle the flow back.

This whole episode is convincing me more and more that we -- PoolForum -- really needs to shift to making specific buy this; buy that recommendations. Now that Amazon is carrying such a wide range of gear, and their indexing is stable (even if their descriptions aren't always correct) so that I can count a link EITHER going to the correct product OR dying safely. I want to work with Mark (mas985) to come up with 4 or 5 standard pump/filter/valve/layout combos so people can not only get the right chemicals and the right test kits, but also the right gear.

Case in point is the BW flow-meter I listed. Five years ago, I couldn't have done that, since the few online companies I trusted had very limited lines of gear.

It won't be perfect, but it will spare a lot of people a lot of grief. And, with the 4 - 6% commission from Amazon, it will help cover costs here.

[TheGoose]

http://www.pentairpool.com/images/product_images/wholegood/WhisperFlo/WhisperFloCurve_new.gifBen,

Looking at the 1-HP Whisperflo curve https://www.pentairpartners.com/productcatalog/productcatalog.aspx I'm trying to figure out what my pump is really pushing.

Taking the fact that I have 20 psi of backpressure, and 1 psi = 2.31 ft of head, then is it safe to assume that I have 46.2 ft of head, or to make it even about 50 ft of total head?

Looking at the chart on pg. 157 and going by the curve represented by "G", which is shown to be the 1-HP whisper-flo (1.65 service factor) it's showing that I should have about 90 GPM of flow.

Taking the low speed chart "B" and considering that I have about 6 psi of backpressure on the system = 13 ft of head. "B" shows at least 40-50 GPM at ~13 ft of head.

Of course I'm not counting head losses from the 2-3 ft of head losses on the suction side so it would be a little bit lower. Also consider that my return piping is 1.5" from the filter to the pool. 90 GPM is way more than the filter is designed for so that would definitely explain why it has never filtered very good.

[TheGoose]

Water is looking slightly better today. FC>5, I turned the pumps off and I'm letting it sit overnight. Tomorrow I'm gonna vac to waste and add sand to the filter.

[mas985]

Taking the fact that I have 20 psi of backpressure, and 1 psi = 2.31 ft of head, then is it safe to assume that I have 46.2 ft of head, or to make it even about 50 ft of total head?
You have to add 3' for the height of the filter gauge above the pump and as you pointed out, there is suction head as well but with 2 suction lines, it should be fairly small so I agree that the flow rate should be at most 90 GPM. Also, low speed is simply half the flow rate of high speed so you really don't need to use the low speed head curve.

[PoolDoc]

Thanks, Mark.

Goose, given that the MAX flow -- for good filtration -- through a 24" filter, like the Tagelus 60, should be 45 GPM or less . . . it's safe to say that you are (1) wasting most of the pumping electricity you are consuming and (2) forcing the filter to fail. If you have 45 GPM on low, you shouldn't even turn the pump onto high, when you backwash.

[TheGoose]

So do you agree with my assessment that I have about ~50 ft of head on the pump and it's probably close to what the pump curve is?

[PoolDoc]

I haven't really checked -- I was just taking what you and Mark said, at face value.

For me to be comfortable estimating your TDH (total dynamic head), I'd want pictures of you skimmer(s), return(s), all equipment connections, pump, filter, valves & piping.

[mas985]

Return head is a know quantity from the filter pressure, ~49' of head. The only unknown is the suction head but as I posted before, that should be minimal because of the dual suction lines. I wouldn't expect more than a couple feet of head IF both lines are kept open all the time. If you want confirmation, I would need more details on the suction lines (diameters, lengths), number suction side valves, and the height of the pump above the pool water level. I can pretty guess the rest and get within 5%.

[PoolDoc]

My bad; should have scanned back for the pictures.

Using the Hazen-Williams calculator here (http://www.engineeringtoolbox.com/hazen-williams-water-d_797.html), for the pipe between the pump and the filter (3xL; 1x branchT; 8' pipe => 20' equivalent length), I get a head loss of 9ft at 80gpm and 11ft at 90gpm. Using the Hayward chart I sent you, Mark, I calculate the drop through the dumb-head Tee layout as 3.5ft at 80 gpm and 4ft at 90 gpm. Estimating the equivalents lengths of the 1.5" piping to the pool at 50ft, and splitting flows evenly at 40gpm each and 45gpm each, I find a loss of 6 ft at 80gpm and 8ft at 90gpm

Taking filter pressure at 49ft, I estimate TDH around 57.5 ft @ 80 gpm(9+3.5+6=18.5) and 62 ft @ 90 gpm (11+4+8=23).

also used Charlotte Plastics Design manual (http://www.charlottepipe.com/Documents/PL_Tech_Man/Charlotte_Plastics_Tech_Manual.pdf)

[Watermom]

Aren't you guys thankful for your math teachers! ;);)

[PoolDoc]

Honestly, I didn't learn to USE math until I was (a) taking engineering classes and (b) simultaneously doing repair work and realizing that I could use some of what I was learning in class to make my work easier.

[Watermom]

understand of how to use math in their daily lives.

That is something I talk about with my students every day. There is no reason to learn math unless you have a use for it. (Of course, some of my smarty-pants kids say then that they shouldn't have to learn it because they have no use for it!) Some day ..........

EDIT --- Rereading that it sounds backwards of what I was trying to imply but you guys know what I mean. My excuse for lack of clarity is that my mind is not on what I was writing right now cuz we are off to Baskin Robbins to get an ice cream cone! :)

[PoolDoc]

There is no reason to learn math unless you have a use for it. (Of course, some of my smarty-pants kids say then that they shouldn't have to learn it because they have no use for it!) Some day ..........

Make 'em do pool problems . . . !

Concentrations, ratios, flow rates, complex volume calculations (liner pools are easy, because they are all straight sides or radius curves, so bright middle school students possess the basic black-box tools to do the calcs), and so on.

[mas985]

Sorry, I was being a little lazy and not running full head calcs. I thought you were interested in an upper limit. But from the picture, it looks like the suction pipe is 2". So if you want full head calcs I need some additional information. If you have already given please post again so I have everything together:

Pump elevation relative to the water level (changes meaning of filter pressure)

Also, I don't remember reading the length of the suction runs. So how long are these and is the diameter 2"?

Filter pressure is 20 PSI correct?

[PoolDoc]

Pump is 2", but you can see the 2x1.5 insert adapters in the inlet & outlet.

Oops. Not quite.

The valve is a 1.5" valve with 2" fittings over the valve -- that would reduce suction flow loss on those segments a lot. Pipe from valve to pump is also 2". But, pipe from pump to filter is 1.5".

Sorry.

[Watermom]

Make 'em do pool problems . . . !

Concentrations, ratios, flow rates, complex volume calculations (liner pools are easy, because they are all straight sides or radius curves, so bright middle school students possess the basic black-box tools to do the calcs), and so on.

Actually, I do. In the past couple of weeks, we have been doing some geometry. They have calculated the circumference of my pool, area of my pool floor, surface area of my pool (cylinder), etc. They all wanted to know if they could come over and swim when school is out. Uh............ I don't think all 140 of y'all are gonna fit in my pool!!

[PoolDoc]

Great!

But what about volume, in both SI and US. And weight! Have a bag of M&M's and give it to the person who can best estimate the volume in 60 seconds.

And flow rate, in GPM, LPM and pounds per hour.

And, from the weight of sand in your filter, the average grain size (0.50mm), and the mass density of quartz, and an assumption of a grain shaped like an equilateral 4-sided pyramid (doubled) . . . calculate the number of sand particles in your filter!

[Watermom]

Oh boy, Ben. You're gonna be in big trouble! Giving M&Ms is a big NO-NO! We can't give any food out for any reason in our district. No pieces of candy for a reward, no pizza parties for rewards. You can't even do any lessons with actual food. No cooking anything when we study fractions, etc. We might all get fat from those 13 M&Ms in the snack size bag!

[PoolDoc]

Well, offer them a bag of all-natural and extra-healthy crickets instead. That will probably motivate the boys, anyhow . . . especially if you give out the crickets in the first class of the day. :o

PS. Walmart sells them, at least around here.

[CarlD]

Just to add my two cents:
In case you haven't figured it out, for now pay no attention to T/A or CH. Don't add any baking soda.

For whatever reason your pH running a little low, in the 7.2 range isn't a problem. Don't "fix" it. Chlorine is actually more effective at lower pH levels and 7.2 is safe for vinyl and safe for swimming.

Carl

[TheGoose]

Suction piping is 2" from the pool. Dual skimmers, one on the near side and one on the far. Pump is at ground level, no more than 3' from the pool level to the pump, probably less than 2' total. Approximately 20-30 ft between the near skimmer and the pump. Filter pressure is ~20 psi clean and I normally backwash about ~28 psi.


Sorry, I was being a little lazy and not running full head calcs. I thought you were interested in an upper limit. But from the picture, it looks like the suction pipe is 2". So if you want full head calcs I need some additional information. If you have already given please post again so I have everything together:

Pump elevation relative to the water level (changes meaning of filter pressure)

Also, I don't remember reading the length of the suction runs. So how long are these and is the diameter 2"?

Filter pressure is 20 PSI correct?

[mas985]

Pump is at ground level, no more than 3' from the pool level to the pump, probably less than 2' total.
This sentence is not making sense to me. Is your pump 3' or 2' above the water line (vertical distance)?

[Watermom]

Well, offer them a bag of all-natural and extra-healthy crickets instead.

PS. Walmart sells them, at least around here.

And YOU buy these, I presume?

[TheGoose]

Sorry. The vertical distance from the water level to the pump suction. The pump is on a small slab, the pipe rises out of the ground about 12" or so, add in whatever the water level is below that, I would say probably a 2' suction lift. I haven't measured it, but it's pretty minor.

Thanks for all the replies.