Opening Pool Questions and Levels

[jrsdws]

Hi all. This is my 7th year with our 27' round 48" deep above ground pool. It has been a pretty easy ride keeping things clear and clean....until last year. As stated in my first post...I had a few algae blooms last year...bought a TF-100 test kit...and found that I had some serious problems with some of my water chemistry. First problem fixed: CYA loomed around 100 so I drained around 60% of my water and refilled. Just finished refilling this morning and have the pump and filter running.

I ran some tests and here are my numbers....a couple of things are pretty far out of whack it seems:

FC: 0
CC: 0
TC: 0
pH: 7.2
T/A: 520 (yeah I did it twice to make sure)
CH: 700 (did it twice also...been filling from a well for years...we have hard water)
CYA: 40

It's about 70 degrees out...pool water is still COLD as we haven't had much sun in Central Illinois yet this spring.

I'm catching alot of crud in the skimmer socks right now and tending to the pool closely as I'm catching alot of stuff.

So where to start? There is algae present now...I'm assuming to start shocking it good and shoot for keeping chlorine level around 12?

I'm curious about the total alkalinity being so high. What causes it? What does it cause in return?

[PoolDoc]

Hi jrs;

Your first priority is commit yourself to never again having to report FC=0 ! You'll absolutely guarantee problems if you let that happen much, and nothing else we can tell you will help much when your chlorine is zero! Use bleach, dichlor, what have you, but get that chlorine up. You can work out how to do it *best* later. Right now, use whatever you can most easily get your hands on.

Set your target levels using the best guess (like below) levels for shock or a little higher -- make sure you use the row that corresponds to your CYA level.

Once that's done, you can look at your TA & CH. I'm going to assume you do NOT have a heater. So long as that's true, you'll only need to watch our for cloudy water from that high CH combining with that high TA. Fixing it is simple, though it takes a little time: lower your pH, and aerate. This page explains how
http://poolsolutions.com/gd/lowering-swimming-pool-alkalinity-step-by-step.html

Dunno why it's so high in the first place: use your kit to test your fill water, and see if it's the source. If it is, it sounds like your water company may be trying to do some "lime-softening" but hasn't gotten the process down.

Ben

[jrsdws]

No heater....I am pounding it with bleach right now but I'm only able to maintain about 4ppm FC. I've put in 36 jugs of bleach!!!

Keep pounding it or try something else?

[Watermom]

Bleach, bleach and more bleach. Try to consistently maintain shock level without letting the chlorine level yo-yo up and down. How much bleach are you adding at a time? Also, run the pump 24/7. Keep an eye on the pH and make sure it stays above 7.0. Keep us posted how things are going.

[jrsdws]

I'm adding 6 jugs (576oz) at a time and checking FC about a half hour afterwards. Pump is running fulltime. I'm using scum socks in the skimmer basket as there is a BUNCH of scum in it. Socks are filling/plugging maybe every 20 minutes or so.

I still don't get any more leaves or anything up from the bottom as I brush or use the basket across it.

I will test pH again right away.

Am I just experiencing a massive algae kill?

[jrsdws]

pH hovering at 7.0....what do I add?

[PoolDoc]

Let it hover there.

Also, please test both FC and TC, and report those results. As far as trying to hold the chlorine stable, I wouldn't worry too much about that -- you can't really do so till you get your algae and chemistry issues resolved. Instead add some bleach during the day, to keep it above 2, but add 6 - 8 gallon doses in the evening. Keep doing that till you can hold high chlorine levels overnight.

Ben

[jrsdws]

In frustration I dumped 20 jugs of bleach in shortly before dark. I let it circulate for an hour and tested.

FC = 39
TC = 43

We'll see how much is left in the morning.

If it's all gone, is it ok to switch to cal-hypo to get the shocking done?

[jrsdws]

Morning readings:

FC = 25
TC = 28

Time to go by another store...or two...out of bleach.

[madwil]

with your TA and CH so high, I would not use anything but bleach for CL... anything else will just add more crud you don't need...
for pH, it will slowly increase due to aeration, so just don't let it get to high- let it get to 7.6 or 7.8, then adjust back down with MA...
with your CYA level, if you shoot for FC 15, you should be good; I wouldn't go above about 20 to much, because that will just increase the amount of loss to other factors without kiling algae; keep it at 15-20 as consistently as you can, especially overnight when it will do most good!
Once you maintain FC overnight with <1 loss, and your CC stays <.5, you can go to normal FC levels of 3-6 (I usually stay on the high side, when it reaches 4-5 I add to 8)...

[jrsdws]

I think I'm getting on the right side of the fight now. Pool is far less dark...a lighter green now...and not as much scum in it.

I'm losing some chlorine since morning, of course, sunlight and algae.

FC = 18.5
TC = 21.5

[jrsdws]

UPDATE: Water is slowly cleaning up I think. FC has dipped a bit today but I'm still in the zone.

FC = 13
TC = 15.5
pH = 7.2

Going to try to keep FC closer to 15 for the next few days.

[madwil]

that's the plan- maintain your FC as consistently as you can, and it will take care of your problem
Keep it at that level until an overnight drop in FC is <1, and your CC (TC-FC) is <.5

[CarlD]

With your FC at that level, don't try to adjust your pH as long as it's reading the way it is. There are two reasons:
1) Measuring pH at FC levels of 15 with a CYA of 40 is highly inaccurate.
2) Chlorine is generally more effective at lower pH than at higher pH.

IOW, keep on doing what you are doing, run your pump 24/7, test and adjust FC 2 to 3 times a day, vacuum to waste everyday. Brush the walls and bottom every day to knock algae loose.

Carl

[jrsdws]

Yep...staying the course!!! Tonight I'm able to see about 18" down the sidewall so we are burning out the algae.

I just ordered more DPD Powder and the FAS/DPD Chlorine Test reagent from the site so I can keep up with it.

I'm hoping we'll be able to see bottom this weekend so I can start working on the next problem.

It looks like we have warm, sunny weather coming next week so it'd be nice to be able to put the solar cover on and get the water warmed up!!

[jrsdws]

Can see through the water to bottom now. Water still has a light green tint to it so I know I'm still killing algae, but I'm making great progress.

It's been easy to hold FC levels within a few ppm pretty much all week....with the exception of a huge rain that really dropped it down.

I have a day off today so I'm going to really scrub the heck out of the walls and floor today several times.

When I backflush I'm still flushing out really dark nasty water so I know I'm really getting the stuff out.

Hopefully by the end of the holiday weekend I'll be pretty squared away on the algae situation so I want to prepare for how to fix the other problems. I'd like to have everything on hand I'll need.

What to work on next and what do I need?

[Watermom]

Read the following guide on lowering alk.

http://www.poolsolutions.com/gd/lowering-swimming-pool-alkalinity-step-by-step.html

As far as lowering your calcium hardness, we usually suggest a partial drain and refill, but since your fill water is apparently extremely hard, I'm not sure what options you have in that regard. ????

[jrsdws]

I think for now I'm going to forget about the calcium hardness issue, unless I find a product that will help that without screwing anything else up.

The pool is now crystal clear and I've been able to hold FC of 12 overnight for 3 nights running.

New test results:

FC: 12
CC: 13.5
pH: 7.8
TA: 520
CYA: 35

I will now start to lower pH so I can begin aerating to lower TA.

Thanks all for all the help....now if the sun would just stay out enough to warm things up we'd be swimming!!!

[madwil]

you can swim in it now, with your current levels...
however, your tests do still show CC, so you may want to keep the FC up another day or two.
I think what you listed as CC might be TC, and only 1.5 CC, but you should still maintain the FC until the CC drops <.5

[jrsdws]

Oops my mistake. Yes CC was 1.5 so TC is 13.5

Water temp only about 70 degrees so we have to be patient....at least I do....the kids might get in.

We'll maintain another day and check it as I lower pH and start aerating.

[Watermom]

You need to keep shocking until you can hold chlorine overnight without losing more than 1ppm and until your CC is no greater than 0.5.

[jrsdws]

Ok...new problem here. We went for our first swim today....nice and refreshing on a 92deg afternoon. However, low on the sidewalls and on various places on the bottom of the pool there are very rough spots...feels like something built up on it there. We also noticed this with the frequent brushings and vacuuming of the pool....the brush would really drag in these spots.

Water looks great. The bottom of the side walls had a little tint where it was rough in spots....brownish/greenish kind of....hard to tell against the blue liner.

Do you think this is scaling due to the high calcium hardness or something else?

It doesn't brush right off....even with lots of elbow grease.

What to do now? Still maintaining FC of about 12 and trying to get it to hold overnight....lost about 2ppm last night.

[jrsdws]

Forgot to mention the brownish/green color brushed away easily so it was probably a bit of algae left. The rough scaley stuff feels like sandpaper and appears white or clear.

[jrsdws]

Chlorine levels finally looking right and holding overnight. I worked on lowering pH slowly with muriatic acid over the weekend...still have a little to go. This morning I moved the return eye up so it's shooting upwards and bubbling hard at the surface for aeration. Here are current readings.

FC = 12
CC = .5
TC = 12.5
pH = 7.5
TA = 500

Will the lowering of pH and TA make the water more acidic and aid in brushing away of the sandpaper like rough spots?

[madwil]

not sure what the rough spots are- but most things will redissolve as you reduce the TA and maintain your chlorine.
If you are holding FC overnight, water is clear (and I see your CC is .5), you don't have to shock anymore- just maintain normal FC levels from now on, based on your CYA level!

[Watermom]

Go ahead and add more muriatic acid to lower the pH back down and then aerate again. With a TA of 500, this is going to be an ongoing cycle you'll need to do, but it will gradually come down.

[jrsdws]

I finally feel like I'm gaining control of my pool. It's taking some time and attention but it's working!!!

We're just maintaining chlorine levels now around 5-7ppm....time for a shock tonight though as there have been lots of swimming with sunscreen, etc., in this heat.

Currently: pH = 7.2 and TA is down to 350 from a whopping 520

The deposits/sandpaper gritty areas are starting to dissolve now....we just keep brushing and they're finally cleaning up.

[madwil]

yep, as you get the TA down, they'll dissolve back into the water...
sounds like you have control now- the pool is acting like you want it to, and usable!
The hard work is done, now just staying on top of it is a lot smoother!
I had about 10 people in the pool yesterday, and water is still crystal clear!

[jrsdws]

Too cold to swim here as of late, but chemistry balance is still underway and making progress. TA is down to 220 with a goal of 120 in sight.

Too all of those working to get your pools water chemistry right....PATIENCE IS A VIRTUE!!!!!!! Don't rush and don't take shortcuts...accept that it all takes time and effort and you'll get there.