Back again, Multiple minor issues

Cowboy46 · Oct 11, 2016

I started a thread: “Rookie Pool Owner needs some advice” on 20 July and kept going with it until 21 Aug. I kept doing what I thought I should do and I think things are going pretty well. I had a black algae problem that took about 3 tough weeks to clear up, no more a problem thanks to y’all!
I’ll give a brief explanation of my issues. Should I start a different thread for each, and where should I post them?

My current stats are:
Cl: >5
pH: 7.6
FC: 8.0
CC: 0.0
CH: 400
TA: 90
CYA: 60

I’ll add another quart of 31.45 MA to lower the pH and try to get the TA down. It seems I have to do that quite often. This is one of my minor issues.
A little side note: I tested my fill water using the TFP method and this is what I got a few weeks ago:
Cl: 4.0
pH: 8.1
FC: 0.5
CC: 3.0
CH: 75
TA: 70
CYA: 0
Which brings me to my 2^nd minor issue: I had to add over 7,500 gallons of water over the past 30 days. We only got 0.2” of rain and it has been dry, humidity around 75% at dawn and down to as low as 25% some afternoons. Is it evaporation or do I have a leak?

My 3^rd issue is: My pool is about 2 inches lower at the deep end than at the shallow end. Didn’t notice that until after we moved into the house. Not sure that it’s a big problem, but with the water loss that I mentioned, the skimmer at the shallow end is sucking air after 3 days and I have to add water again. Is there a reasonable way to fix that, or do I just have to deal with it?

My last issue is: I had a problem that I brought up in my previous thread about my 7 year old PureLink1400 cell. I replaced it, but couldn’t tell for sure if the new one was working correctly. I assume that it is since I have only had to add 2.25 gallons of bleach in mid-August to 6 September and have not added any since. The FC got down to 4.0 on 19 Sep but now is up to 8.0 without any bleach added. My SWG is set at 90% for 8 hours per day. Does that indicate the SWG is working?

Thank you for putting up with my long post and anticipate some good advice on what I should do from here.
Thank you.

Catanzaro · Oct 11, 2016

You probably have a leak, unless there is a tremendous amount of splash out, back washing, etc. Place a piece of blue tape on the skimmer or mark the area. Then go back a few days later, exactly at the same time. Usually 1/2" per day at most. Hard to tell. About 25% water replacement in 30 days does not sound normal. Please report back with results after a few days.

Your pool is not even (strange, but could happen). Keep the water level on the skimmer, deep end 3/4" of the way up, which should compensate to about 1/2" way on shallow end. I think it is the leak that is causing this to suck air after a few days.

I do not have a SWG, but it appears that you are in good shape with the new cell. Adding about 2.25 gallons of liquid chlorine when it is hot is fine. Texas is a hot State.

Jimrahbe · Oct 11, 2016

Cowboy,

If your pH is 7.6 why in the world are you adding anything? A lot of SWG pools run a pH of 7.6 to 7.8. Just leave it alone until it goes over 7.8

Jim R.

Cowboy46 · Oct 12, 2016

Jim,
I am just doing what is recommended when I use “Pool Math”. It says “To lower TA you reduce pH to 7.0-7.2 with acid and then aerate to increase pH.” My TA is always high (as high as 140 once back in July). When I was tracking it close, I got it down to 70 using the Pool Math logic. I got a little lazy with it and its back up to 90. I’m not sure how much of a problem the high TA is.

Catanzaro,
I have been tracking the water level fairly close. It generally decreases about 1/8 to 3/8 inches per day. It wasn’t too bad when we were getting rain fairly often, but it’s been really dry since 1 September. Sometimes I will close the valve to that skimmer when the level gets down and the basket won’t stay full until I get a chance to fill the pool again.

Thank you both for the replies. It’s been helpful.

Catanzaro · Oct 12, 2016

It generally decreases about 1/8 to 3/8 inches per day.

In Texas, this could be very normal. But 25% of water replacement in one month seems odd. One could literally use 3" tablets and never really have to worry about CYA issues, only possibly PH. A few gallons of bleach and you would be all set. Personally, I did not have to fill up the water too much as we had consistent rain and really only loose about 1/8" per day max.

pooldv · Oct 12, 2016

1/8"-1/4" per day is a pretty normal evaporation rate.

needsajet · Oct 12, 2016

Per your questions:

Keep all your issues in the one thread. It makes things a bit easier to understand when we can get the whole picture in the one thread.

To rule out a leak (I don't think you have a leak), do the bucket test described here: Pool School - Leak Detection

Your water looks fine and has been covered by the others above. Lowering TA is worthwhile if you find that acid is needed too frequently for the rest of your life, then by all means lower it. If adding acid a couple of times a week is fine, just let your TA drop slowly on it's own as each bit of acid is added. TA 90 isn't too bad, and it has gone up due to refilling followed by evaporation.

I'm afraid there's no easy fix for an inground concrete pool that's out of level. What you're doing now is the only cure that doesn't involve a jackhammer. When the pool needs re-plastering, then it could be fixed by raising the lower end (remove the coping, deck and waterline tile, add concrete to build up the low end, feathered out to the high end, replace the waterline tile (level this time) and the coping and deck.

Your SWC is working great. Running it for 8 hrs per day at 90% is adding about 1.3 ppm FC per day for your pool, which is reasonable for this time of year (sun lower in the sky and colder water)

I'm guessing that your first number (Cl >5) is from the OTO chlorine test (the yellow one). You can skip that test if you're doing the drop-based FC test.

Our normal convention for water test reporting looks like this:

FC: 8.0
CC: 0.0
pH: 7.6
TA: 90
CH: 400
CYA: 60
And last number for salt that you're aware of
Salt: 3500 (for example)

- - - Updated - - -

If you have a skimmer plate in the higher skimmer, you could remove that to delay the vortex starting and allowing air into your suction side.