Dusty Bottom/Cloudy Water Issues

[MattTexas]

I have a 15x30 AG pool that was installed last year. About 11000 gallons. It has a Heyward pump and sand filter with multiport valve - it can vacuum to waste and recirculate.

About filtration media: The sand tank has zeolyte. According to label recommendations on the zeolyte, when I installed it last year, I only included about HALF the amount of recommended sand. Until now, I haven't had filtration issues, but the tank DID get shaken around a lot while I had it winterized - It even got rolled on its side some. However, it was sealed at that time.

About location of pool: pool is located partially underneath a pecan tree. Due to the nature of our yard, we just didn't have a choice here when we installed it.

Chemistry:
Ph=7.4
Alk = 125
CYA = 40-ish
FC = 3.0 (last test for CC, about 3 days ago, was at <.5)
CH = circa 380 (I have trouble reading the color change on this test)
Phosphates - my pool store tested today and indicated no phosphates

Here is the problem: The pool has been opened since mid-March. From the start, I noticed that a very fine brown-ish "dust" was settling in the crevices of the pool, particularly along the edges. In addition, during the last few weeks, it has rained 2-3 times. After raining, the bottom of the pool tends to develop green patches, and a very fine layer of what I would call "dust" tends to fall across the bottom of the pool. When the pool is in this condition, water clarity is very good, but the walls and ladder tend to start turning green.

In response to this, I always shock and brush. I also add algaecide. Chlorine levels tend to go down to about 3ppm overnight and I then maintain them there. I run the pump constantly. I also run an automated cleaner on the bottom of the pool for about 3 hours. If I brush again the next day, I can see that I am again stirring up a layer of "dust" off the bottom of the pool.

The green continues to gather in a few isolated patches on the walls overnight, and I can also see a layer of green covering various crevices in the portion of the ladder that is in the pool.

The pool is blue-cloudy - moreso after I brush and less so several hours later. I can see the bottom of the pool, and even see the walls/bottom on the opposite side of the pool, but it is still obviously cloudy. I have tried water clarifiers and organic enzymes as well as oxidizing shock. Nothing seems to help.

I haven't yet tried this, but I suspect that, if I turned off the pump overnight, all of the cloudiness in the water will disappear as the "dust" settles back on the bottom. I'll end up with clear water and a cruddy looking layer of the dust-like stuff on the bottom.

Here are the things I HAVEN'T yet tried:

1. Let it settle on the bottom and vacuum to waste
2. Try to maintain FC at 15 until it clears (I've seen this recommended on the boards here)
3. Check for filtration problems (Don't really know how to do this)

Any suggestions?

[aylad]

Hi, and welcome to the forum!!

It sounds like you're not completely killing the algae before you let your chlorine drift down. With a CYA around 40, you need to run your chlorine level up to 15 ppm and hold it there not just overnight, but until you can go overnight without losing more than 1 ppm of chlorine. This usually takes more than one day....but it's the only way to really kill off the algae. You need to thoroughly brush the pool just after the chlorine addition, as well, with special attention to the places that you know the green is growing. Don't add anymore clarifiers, algaecides, or other goop--just plain chlorine will do the trick.

Regarding filtration problems--do you have a working pressure gauge on your filter? When you run your pump, does the pressure rise any? When you backwash, what color is the stuff coming out? You can check your filter (and with the treatment you describe it got during closing, I would!) by adding a handful of DE to your skimmer and watching the returns to see if it blows back into the pool. If it does, then your filter will need some work. If not, then the DE will coat the sand in the filter and will help it collect finer stuff than the sand would alone.

How are you testing your water?

[MattTexas]

Janet-

Thanks for the quick reply! I do have a working pressure gauge. It rises whenever my pump is primed and the system is set on filter, but it never seems to increase in pressure from there. I have backwashed a couple of times in the last 2-3 days. The first time, I got LOTS of green. The second day, I got some brown. It does seem to be catching stuff - more generally speaking, whenever I backwash, I tend to get a lot of brown water before the stream clears up.

Any suggestions on the best place to buy DE?

Re, my testing: I have a K-2006 kit. For day-to-day/quick-n-dirty readings, I also keep a FAS-DPD kit handy.

[aylad]

Just re-read your post and realized that you have zeo instead of sand--don't add any of the DE to it yet, let me check with Pooldoc or one of the other filter gurus and make sure that it won't create problems. You can get DE at a pool store, but I think I also saw Ben post a smaller quantity that he found through Amazon. At any rate, don't add it it until Ben says it's okay....

Janet

[MattTexas]

An update: yesterday I chlorinated the pool in a manner calculated to get it well above 15ppm. I didn't do my K-2006 test on it this morning, but the DPD test kit showed it was still WELL over 5 ppm. Based on the very dark color of the liquid, I think it probably held pretty well overnight, but the DPD kit won't register the exact reading above 5ppm.

[Watermom]

Like Janet said above, you need to maintain shock level until you can go from sundown one evening until within 2 hours of sunrise without losing more than 1ppm of chlorine, and you have no greater than 0.5CC. Then, we usually suggest holding the chlorine high for one additional day for added insurance. Only then, can you let the chlorine drift down. So, you really need to use your K-2006 kit so you can accurately see what is going on.

[MattTexas]

Got it.

Is it okay to let it drift down to 15ppm, assuming it is higher than that right now? 15ppm is the amount recommended by Janet, but I had shocked it at a higher level last night before I saw her post. Not sure, but when I do a K-2006 reading on it, it might still be higher than 15ppm at sundown today. <G>

- Matt

[Watermom]

Yes, it is ok to let it come down to 15. Test it this evening and if it hasn't dropped to 15ppm, don't add any more chlorine. If it has, add enough chlorine to take it back up to 15. By the way, what are you using to chlorinate with?

[MattTexas]

I'm using this stuff: http://www.lesliespool.com/Home/Pool-Chemicals/Pool-Shock/14181.html

I apply it into the skimmer. Yeah, I know (now) that I could use bleach from the grocery store, but I bought this in bulk, so I thought I might as well keep using it as long as I have it. Do you see anything about it that could be harmful? My assumption is it is just granular chlorine that dissolves quickly.

I'd also kind-of like to know for future reference. I want to support my local pool store, and I don't mind buying chlorine there, even if its more than I'd pay for grocery items at Wal-Mart.

[MattTexas]

Update: last night I brought the level up to 15ppm. As of about 2 hours after dawn this morning, I had lost 2ppm (reading was 13). No growth showing on walls. A little less cloudy, but there is a large buildup of brown-ish "dust" in the crevices of the floor.

On a related note: anyone have advice on whether I should put some DE in the skimmer basket to test the filter and to help the filter catch smaller particles? I have zeo sand in my filter.

[PoolDoc]

Hi Matt;


Your chlorine from Leslies is 73% strength cal hypo -- it's good stuff for this purpose.
You do NOT need to test your filter with DE; it's been catching algae, so it's working fine.
You will improve your kill by BRUSHING all the areas where algae has appeared, even if you can't see algae there now.
You should brush in the evenings AFTER adding chlorine.
If you will raise borates in your pool to around 60 ppm, your pool will be more resistant to this type of algae.
BUT, borates are something in addition, not a replacement for chlorine.


It's much easier to answer your questions, when we have the details about your pool in one place. We often 'waste' the first few posts back and forth collecting information. So, please complete our new Pool Chart form -- it takes about 30 seconds, but will save much more than that.
Pool Chart Entry Form (https://docs.google.com/spreadsheet/viewform?formkey=dHBLTzdpX19DZVlzUTRLOTU5ZFlZSWc6M Q)
Pool Chart Results (https://docs.google.com/spreadsheet/ccc?key=0Ahjo2iDF0aJgdHBLTzdpX19DZVlzUTRLOTU5ZFlZS Wc)

If you are interested in the borate thing, you'll need about 20 boxes of 20 Mule Team borax, and about 6 gallons of acid - maybe $150. Don't do this if your pool is leaking, or if you are planning to drain it anytime soon. And, ask before you start. There are some other things to do.

[MattTexas]

Update for Jun 13: Water was at 15ppm at dusk last night. Just tested about 2 hours after sunrise. It is at 14ppm with <.5 CC.

HOWEVER, it is still moderately cloudy. I can see the bottom of the pool, but it is very murky and blue.

What needs to be done to get rid of the cloudiness? Let everything settle and vac?

Right now my pump is running 24 hrs/day.

[Watermom]

Looks like you are making progress but since it has only been one day since you reported a 2ppm chlorine loss overnight and your pool is still cloudy, I'd keep the chlorine at shock level for another day and repeat the overnight test again tomorrow night.

Is your filter pressure rising? For now, keep your pump running 24/7.

[MattTexas]

I was out of town last night, but I had my teenager add enough chlorine to keep it superchlorinated until I get back. I'll run the test again tomorrow.

As to the pressure rising - the answer is "not really." For whatever reason, this tank has never showed increases in pressure over time when I use the filter. I flush lots and lots of brown and (occasionally) green gunk out of it when I do backwash, but the pressure never seems to rise. I've had two gagues on it, and they've both been this way. Not sure why.

[MattTexas]

Still at it.

I was at 16ppm at dusk last night, and I tested about an hour after sunrise and was at 12ppm.

Will repeat again tonight.

[Watermom]

Yes. Since you lost that much chlorine overnight, you are still fighting something. Continue doing this. (Re-read post #6 above.) You also need to be checking your CC reading each morning. And, any morning that you have had too big of an overnight chlorine loss, add enough chlorine that morning to get the level back up to shock.

[PoolDoc]

A little less cloudy, but there is a large buildup of brown-ish "dust" in the crevices of the floor.

If this is occurring on vertical, rather than horizontal surfaces, it's mustard algae, not debris. It *may* be mustard algae, regardless.



anyone have advice on whether I should put some DE in the skimmer basket to test the filter

Yes, but only a few cups.



and to help the filter catch smaller particles? I have zeo sand in my filter.

No. This doesn't always work out well, and can cause problems in some cases.

[MattTexas]

Ben-

This is DEFINITELY on the pool floor, and its generally falling into crevices that are perpendicular to the water circulation pattern, i.e.

----> | |


They tend to be along the edge more than the center, but definitely on the floor of the pool.

I'm brushing it at dusk every evening - at the same time I chlorinate.

Pump still going 24 hrs.

- Matt

[MattTexas]

@PoolDoc-

You had earlier indicated I didn't need to test my filter because you believed it was "catching algae." I think you based this on my report that, when I backwash, I get green and or brown gunk.

Would there be any harm in trying the DE test just to be sure?

Thanks to everyone for the ongoing help!

[Watermom]

There is no harm, but it really isn't necessary. If it is catching brown and green gunk and your filter pressure is rising, then it is working. If it wasn't working, it wouldn't be catching stuff because it would be blowing it through the filter and back into the pool and thus your pressure wouldn't be rising.

[MattTexas]

@Watermom-

I AM getting gunk when I backwash, but... see #14 above. For whatever reason I've never been able to measure a rise in pressure on my tank, even if I wait many weeks between backwashes.

[MattTexas]

Update:
Measurement at dusk last night 16ppm (0 measurable CC)
Measurement 1 hour after dawn today 16ppm (0 measurable CC)
Will maintain chlorine levels at 15+ today and repeat again tonight.

I backwashed yesterday and got plenty of brown gunk, but still curious about why my pressure gauge doesn't rise on this tank (see #14 above).

[Watermom]

Good that you lost no chlorine overnight and have the CC reading of 0. How does the water look? Keep filtering 24/7. I have no idea why your pressure gauge isn't rising. Maybe someone else will.

[MattTexas]

Water still looks blue/cloudy. Maybe a little less so than on previous days. But that may also be wishful thinking on my part. <G>

Still catching brown-ish "dust" (algae?) in the crevices on the bottom, and I definitely still have a very fine layer of the same stuff falling all across the pool floor. I stirred it up with my brush where it was visible.

Still running pump 24/7.

[Watermom]

In an earlier thread that I was helping with today, I wrote the following to somebody who was complaining that they constantly had sand all over their pool floor. I'm going to copy and paste my reply to them here. It doesn't totally apply to your situation, but part of it may since you aren't sure what the brown stuff is on the bottom of your pool.

Below is what I wrote in the other thread:

Is it possible that it is just dirt/dust?

My pool has a vinyl liner and underneath it is a foam pad that is taped together with tape. You can see these lines underneath my liner. I can vacuum my pool and have it look spotless but then hours later when the water quiets back down, the dirt/dust that is in suspension while I am vacuuming drops back down and always resettles in those 'lines.' No matter how slowly I move that vac head around and no matter how spotless it looks when I am finished with the vac, it reappears. This was also true in my previous liner pool. It is no big deal, though. Of course, I want my pool perfect but hey, there is dirt out there in the world and there is no way I'm going to keep it out of my pool. As soon as we get in to swim, that little bit of dirt gets swished around back into suspension again and you can't see it.



Now, Matt, what I want you to try: Turn your pump off for awhile (like maybe overnight tonight) and see if stuff settles on the floor. Then, turn the pump back on and very slowly vacuum the pool floor. Then, wait and see if that makes a big improvement. If it is dirt/dust and you are brushing the pool frequently, you are getting it all into suspension and that could be clouding up the water.

I'm not saying you didn't have algae; you obviously had something going on with CC readings and with overnight chlorine loss. But, I'm just wondering if part of it could actually just be dirt/dust. How long has it been since you vacuumed the pool?

[MattTexas]

I think there is a good chance it is dirt/dust as well. I just don't know.

Do you think I should vacuum to waste or to recirculate? I've been advised before to vacuum to waste, but it seems to REALLY take a lot of water out of the pool. In fact, I may need to stop, re-fill, and then continue several times to keep the water level above the skimmer. On the other hand, if it is dirt/dust, and if it is going into suspension (and thus, I would assume, through the zeo sand filter system), vacuuming on recirculate probably isn't going to help.

Also wondering about my vacuum head. Around the edges, it is covered with bristles, but it has a hole in the middle that draws in the water. This is very counter-intuitive for me, as it would seem to stir up the gunk before it can be pulled in by the intake. I've seen vacuum heads with no brushes, and just rollers that keep the head about 1 cm above the pool surface. These seem like much more sensible items to use for a problem like this. Thoughts?

Thanks, again, Watermom for all the help!

[Watermom]

You are right that vac to waste uses a lot of water. If your filter is working properly, you should be able to vac to filter. Maybe use a skimmer sock also to see if it will catch the tiny particles you vacuum up. Watch the filter pressure, though. If the skimmer sock causes the flow to be blocked too much, your pressure will go up. By the way, if the stuff goes back into the pool when you vac to filter, then you have a problem with your filter.

Vacuum heads with rollers are for inground pools. You just need to move the vac head really slowly! The brushes may cause a little of the dirt to get into suspension but shouldn't be too much if you move it slowly. The purpose of the brushes is to disturb the debris just a little so that it can get sucked into the opening. I always get into my pool to vacuum because I think it makes it easier.

(By the way, recirculate totally bypasses the filter, so you would never want to use that setting when you are vacuuming or trying to filter stuff out of the water.)

And ...... you are welcome!

[MattTexas]

Yes, I meant "filter" not "recirculate." Having trouble getting focused today, I guess. :)

[BigDave]

I'm pretty sure that West Texas is known far and wide for it's dusty dirt.

[MattTexas]

Update: I have tried vac-ing to filter per @Watermom's suggestion in #27. Didn't seem to help and now I'm also noticing sand residue in the hose after I backwash. Here are the details:

First, I left my pump off for about 13 hours. After that, the pool had cleared SOME although it was still a little cloudy.

Then, I started the vac process.

To be clear, since I got confused about this yesterday, I was set to FILTER on my sand tank. I went V-E-R-Y S-L-O-W-L-Y. I tried to take my time to make sure that I wasn't stirring stuff up before it could get into the filtration system. I also tried to work my way around the pool so that - as I progressed - I only stepped on areas that had already been vacuumed.

There was DEFINITELY a thin layer of something on the pool floor, all across the floor. In addition, large clusters of brown-ish "gunk" had settled in various pool crevices. I slowly passed my vac over all this stuff, and it vanished.

HOWEVER, there was a problem. After I got a little way into the process, I noticed that the pool was definitely becoming a little cloudier around the return inlet on the pool. The area where I was vacuuming seemed okay, but the return area was definitely a little murkier. I didn't take this at a good sign, but I nevertheless finished vac-ing the entire pool floor. I covered every square inch of the pool floor using the technique I described above. Once I was done the pool was a less clear than it was before I started. Its all a very nice shade of blue - its just murky.

Then, I backwashed, just to see if I had caught anything. Sure enough, once the backwash started I got a stream of white, but extremely cloudy water. It even looked cloudy sitting on the ground in pools. I would describe it as milky-white. Eventually, the backwash stream cleared. I then rinsed and restarted the filter.

Thereafter, I discovered a NEW problem. When I disconnected the backwash hose, I noticed a ring of sand (zeo?) around the valve where I connect the hose. I also noticed a little sand sticking to the inside of the area of the hose where it was connected to the backwash valve. Didn't notice it anywhere else in the hose (e.g., none at the other end of the hose and didn't feel any sand in the hose as I was rolling it up.) I've never noticed this before, and I think I would remember it if it had happened.

Now that I'm sure I'm free of algae, I'm pretty sure the pool has a lot of fine particles that are just getting through the filtration system. Here are the options I'm considering, though I'm open to others:

1. Try the "DE" test by putting a cup or two of DE in my filter to see if it comes out the inlet.
2. Putting enough DE in the fliter to "help" the zeo in my tank get the smaller items.
3. Filter sock. (Anyone had luck dealing with a problem like this using a sock?)
4. Floc and vacuum. However, I'm worried about whether I won't end up with the same problem, even after flocing.
5. Let everything settle REALLY well and vacuum the floor to waste. This will be a LONG process. I'll have to stop after 10 mins of vac-ing to get the water level back up to the skimmer (which will take about 30 minutes). It will definitely be a Saturday afternoon project.
6. Honestly, it would be just as easy as #5 to just drain the pool down to about 18" and then re-fill.

I'd really like more options. Can anyone think of any?

[MattTexas]

Re #30. Another possibility I've been reading about here is that my 1.5 HP pump is blowing some finer materials through instead of filtering it. Is that a possibility?

[aylad]

Yes, that's a possibility. That's why I asked in the first post in this thread whether or not your pressure gauge is rising. You indicated that when you backwash you're getting brown and green stuff washing out--is that still true, or is your backwash water clear? How does your water look at this point?

If your pressure gauge isn't rising, and you're no longer washing out brown/green stuff with your backwash, then I would suggest keeping the pump on recirculate until you're completely finished shocking the pool and it all is dead, and then shutting the pump off and letting it all settle to see if you can vac it out to waste.

[MattTexas]

@aylad (#32)- No pressure rise. I've NEVER had a pressure rise with this pump since I got it last Summer, which is why I'm starting to suspect that the pump is just pushing water through the filter faster than the filter can handle it. I DO get some backwash. Green if I'm fighting algae, brown if its been running several days/weeks, milky-white if I recently backwashed it. But my working theory is that the finer stuff just pushes right on through due to the amount of pressure in the tank.

[aylad]

Does your gauge stay at zero all the time? If it moves, then does it go back to zero when you turn the pump off?

I tend to agree with your working theory--and in that case, I stand by my recommendation in the last two lines of my above post.It's what I would do in my own pool in your situation, anyway. :)

Janet

[MattTexas]

No. It moves up when I turn the pump on. But it doesn't rise over time.

[MattTexas]

Update: the pool is looking slightly clearer today. I want to try adding some DE (see #30 above) just to see if its getting some of the finer particles. I loathe the thought of vac-ing to waste because of the amount of water it will take.

Still convinced I've got a problem with an over-powered pump creating too much pressure for good filtration, but I also think it is catching SOME of the stuff.

Anyone have experience using a handful of DE with zeo sand?

[MattTexas]

Well, folks, the DE trick just may have done it. I put a couple of handfulls in last night, and this morning, I had a very clean looking pool.

I had some dust settle on the floor, but it was all clumped together in 3-4 spots, so I just set the vac to waste and sucked that stuff right now.

Feels nice to have something that resembles a clean pool again. Many thanks to Watermom, Janet, and PoolDoc for all the help!

[Watermom]

Great news! Now time to enjoy that pool! And, you are very welcome. We are all very glad to help!

[aylad]

That's good to hear--and you're the first that I know of to try the DE trick with zeosand. Now we know that it probably works with zeo, too....did you by any chance open your filter up and see if it gunked the zeo up?

[MattTexas]

No. I really didn't want to open up my filter unless absolutely necessary - especially after it seemed (finally!) to be doing something. I did have *some* DE blow through the filter and into the pool after I added it, but it wasn't much at all. Most of it is presumably somewhere in the tank.

[aylad]

OK--but until we know what the DE did to the zeo, we won't be recommending it for zeo folks to try. If, during this season, you have to open the filter for any other reason, just keep this thread in mind--and let us know what you found. :)

[williamsjp]

I don't know if your problem is solved but it all happened to me as well.

Mine was pollen silt...I put 1 cup of DE in my skimmer (I have a sand filter) moved the water for a couple of days steady TA-DA it's gone.

I will warn you though backwash everyday because if you don't the silt will still be your sand and blow right back in. The other thing is your pool will be cloudy for awhile if you don't put clarifier in there pretty quick.

[aylad]

I don't know if your problem is solved but it all happened to me as well.

Mine was pollen silt...I put 1 cup of DE in my skimmer (I have a sand filter) moved the water for a couple of days steady TA-DA it's gone.

I will warn you though backwash everyday because if you don't the silt will still be your sand and blow right back in. The other thing is your pool will be cloudy for awhile if you don't put clarifier in there pretty quick.

The issue here is that the poster has zeosand, rather than filter sand, and we're still not sure of the effect of the DE on the zeo. Thanks for your comment, though, because it's just one other documented case where what we teach here does work!

Janet