Balancing chemicals is killing me

[bplaxico]

Hi, I’ve battled this pool for 2.5 years. One common denominator is high pH, low TA, and low FC. Weirdly, it looks pretty good. I wonder how many times I’ve used SLAM this season alone? Anyway, I’ll post current results, because they don’t very much.
FC 0.5
CC 0
pH 8+
TA 50
CH 250
CYA 35-40

Every time I start SLAM, I lower PH to about 7.2. Most of the time I raised TA first, but doesn’t really matter. Yes, I follow FC/CYA chart. FC will hold several days, pool will sparkle blue, and I always pass OCLT. I’ll let FC drift down slowly, but pH never goes below 8. FC will stay between 2-4 for a couple days, then drop to 0. I brush and vacuum religiously. When I add bleach, it will raise it only briefly, and make pH test look like cherry koolaid. Where am I going wrong? Thanks in advance y’all!
Brent

 

[AimeeH]

Hi there,

How are you measuring your PH? Is it always with the Taylor drop test? Are you aerating? It seems highly unlikely your PH would be that high with a TA of 50. Your FC is way too low for your CYA number on that list of results. It seems several things are a bit off.

 

[Catanzaro]

When I add bleach, it will raise it only briefly, and make pH test look like cherry koolaid. Where am I going wrong? Thanks in advance y’all!
Brent

Brent:

You just answered your own question. Adding bleach and then testing PH is going to have this type of effect. You should always test PH before any additions. Liquid chlorine is PH neutral. PH will increase with additions and come back down once the chlorine burns off.

The second part of the problem is that your CYA may be off, thereby burning off more chlorine than you want.

Please do the following:

1) Only add liquid chlorine real early in the morning or real late at night (out of the sun). You may be adding it during sunny times.

2) Make sure your bleach is fresh and dated within 60 days.

3) Make sure that you are adding based on the correct size of the pool. A 12' deep end sounds deep. Maybe you are off on the pool size (hard to tell).

4) You state in your signature that brushing is done regularly and you have an inexpensive bottom cleaner. Are you positive that nothing is being missed?

Sounds to me like you could have a circulation problem. One skimmer and one return (brushing needs to be done at least every other day). What about main drain, what is the BH control plate? I would have both the skimmer and main drain pulling water with this type of design and brush more often to see if this reduces any problems you are faced with.

 

[JohnT]

FC will stay between 2-4 for a couple days, then drop to 0.

This is your problem. You should never let the chlorine level approach zero. It allows algae to get started and then future chlorine additions are consumed fighting it.

 

[bplaxico]

Thanks for response, I completely agree, that’s why I’m back on here. I use the Taylor kit mostly, but I’ll double check it with others I have. The amount of bleach I’ve had to use is absurd. I’ll bet I’ve rechecked CYA 15 times this summer. Obviously, had to buy supplemental reagents. pH will lower with MA, but only briefly. I don’t check it during a SLAM. Sodium Bicarbonate will raise TA, but again, briefly. Although I only have one skimmer and two returns, flow is good. I clean cartridges well about once a week. I’ve gone longer in between cleaning them and shorter, no change.

 

[bplaxico]

Cantanzaro just saw reply. Baker-Hydro control plate is a plastic diverter made to “evenly” pull through skimmer and main drain. I always add bleach, less than 69 days old, closet kept, at night. I’ve measured the pool multiple times. I know it doesn’t make any sense. Thanks.

- - - Updated - - -

As far as CYA, I’ve poured it back into plastic bottle, poured it back into gauge. Never really varies.

 

[Catanzaro]

Cantanzaro just saw reply. Baker-Hydro control plate is a plastic diverter made to “evenly” pull through skimmer and main drain. I always add bleach, less than 69 days old, closet kept, at night. I’ve measured the pool multiple times. I know it doesn’t make any sense. Thanks

I have a friend (who had a pool, but sold the house), in where he had one skimmer and main drain in the deep end, and one return in the shallow end. A 20,000 gallon pool with drop in steps. If he did not brush the pool daily, algae spots would show up. The pool was all about dead spots. I remember you stated 2 returns, but others may have different thoughts. Try maintain a 10% CYA/FC ratio after your SLAM for a while and see what happens. But try brushing more often as I am convinced that this is the issue (if everything else is in tact).

I was at this house so often that I knew the pool better than he did. He followed the minimum CYA/FC recommended levels and also had the TF-100 kit. Except he did not join the forum. The pool usually had no issues in the early spring, and late summer. But, In the 90 degree + days, if he skipped a few days of brushing, like clockwork algae spots even at high chlorine levels. There were just areas that chlorine was not reaching (that simple, for at least that pool).

 

[bplaxico]

Good to know someone else has had similar problems, kinda. I too get spots, but I brush 2-3 times a day at least. I like 10% idea, but I’ve even kept it at 12-15 FC for weeks. The spots are a bit strange. Sometimes in shallow end with same steps you mentioned, but almost always a thin thread from or to main drain. It runs on side closet to skimmer from about 7’ from shallow end. Like a light green road line to or from skimmer, if that makes sense. Thanks

 

[Catanzaro]

Brushing more than once per day is not needed and just over kill. Something else is going on, and again I am betting on circulation. You may want to look at the circulators. The One & Only Circulator to improve and increase circulation. But be forewarned as they do not solve all problems. Call the company directly to see if the mega ones fit as these are better. May be worth a try.