CYA dropped that fast?

[MiguelACA]

Roughly 2 weeks ago I stopped using pucks and switched to liquid chlorine. My CYA had been at 100, then dropped to 90 about 4 days later, assuming I did the test right. I tested again today and it's at 50! I did the test multiple times. Using the reagent in the kit and the refill i just got last week, same results. 50/50 water/reagent. Could see the dot at 50 then not at 40. For about 3-4 days, the pool was much warmer than the outdoor temp and it's still been pretty sunny here in Houston. I also noticed that my auto fill had been running constantly. I checked it today and noticed it was set for water level higher than my auto drain. I'm assuming between evaporation, the auto fill constantly pumping in fresh water, the auto drain draining to keep the pool level, and water loss from splashing and jumping in the pool, which they kids do A LOT, AND whenever we have a large number of people in, the water level rises almost above the skimmer (it's a small pool at only 5k gallons), so the auto drain is going crazy dumping the excess out.

Now that I have written all this out, it makes sense that I've lost so much water.

I did shut off the auto fill and will check for water loss just in case there is a leak somewhere.

Thoughts?

 

[MiguelACA]

Halloween weekend, the pool was kept at around 90+ if that makes a difference

 

[mknauss]

Elevated water temperatures do breakdown CYA in pool water a bit quicker but overwhelming is your water exchange. Do you have a CH test that indicates that level of water change?

 

[MiguelACA]

CH
9/24-250
11/1-140
11/2-400
11/6-330

CYA
9/24-100
10/22-100
10/29-90
11/6-50

Seems like it reduced a significant amount around the Halloween time, Friday through Sunday, the heater and pump were running 24/7 and had a lot of activity in the pool.

Thoughts?

 

[MiguelACA]

@mknauss

Pool water is currently 86 degrees, I'm not sure if temp matters when testing CYA

 

[mknauss]

Your CH cannot be that variable. Did you add calcium chloride to raise the CH from 140 to 400 in one day?

Water temperature does not effect CYA testing.

 

[MiguelACA]

Your CH cannot be that variable. Did you add calcium chloride to raise the CH from 140 to 400 in one day?

Water temperature does not effect CYA testing.

Yes, i added about 14lbs

 

[MiguelACA]

@mknauss

See if this helps

PoolMath Logs

 

[mgtfp]

What's interesting is that your CH basically keeps dropping. First from 250 to 140, but CYA was constant at 100 (did you still use pucks back then?). Then you added calcium chloride, but CH, and now also CYA, keeps dropping. How do you top up water losses, do you have a water softener or very soft fill water in general?

 

[ajw22]

You described that you were losing water through your auto drain and it was being replaced by your autofill. Your pucks had been replenishing the CYA you lost from the drain. Now with liquid chlorine you are seeing the effects of draining in both lower CH and CYA.

Fix your drain problem and your water chemistry should stabilize.

 

[MiguelACA]

What's interesting is that your CH basically keeps dropping. First from 250 to 140, but CYA was constant at 100 (did you still use pucks back then?). Then you added calcium chloride, but CH, and now also CYA, keeps dropping. How do you top up water losses, do you have a water softener or very soft fill water in general?

I used pucks up until about 3 weeks ago. Water is topped off from an auto fill from the tap. Haven't actually tested the fill water.

 

[MiguelACA]

You described that you were losing water through your auto drain and it was being replaced by your autofill. Your pucks had been replenishing the CYA you lost from the drain. Now with liquid chlorine you are seeing the effects of draining in both lower CH and CYA.

Fix your drain problem and your water chemistry should stabilize.

This is what I'm thinking, i guess I'm just bouncing my thoughts of y'all with more experience. I'll get the auto fill squared away so it's not dumping more water than it should

 

[mgtfp]

And compare your household water use at the water meter with the auto fill turned on and off.

 

[MiguelACA]

As an update, I adjusted the auto fill and forgot I had taken out the eye balls from the auto fill and auto drain when I was having issues and never put them back on... The the fill and drain just had open pipes letting as much water get in and out as it wanted. With the eyeballs in, it should keep everything in check and working as it should. My CYA is holding. Guess my goof saved me from having to actively drain and fill the pool to where it needed for the CYA to level out.

 

[MiguelACA]

All the moving and swimming was causing water to get forced into the open pipe and draining out during heavy pool use... It's a small pool lol

 

[MiguelACA]

UPDATE

I noticed that my CYA and CH kept dropping even after adjusting the autofill and eyeballs on the overflow and autofill. I also noticed that my curb was ALWAYS wet! Water was coming out of the drain that the overflow taps into. The PB sent his project manager who adjusted the overflow, claiming it was set too low. He also used dye to check for leaks. Kept losing water and chemicals, curb was still wet. I took measurements and recorded everything and called the PB again, requested that the project manager and he come by to take a look as its costing time and money. PM showed up first and took measurements and assured me everything was fine..but couldn't explain why my curb was wet or why my pool was losing water...I confirmed it was pool water coming out of the drain by the street by testing it for chlorine and testing the fill water to make sure it didn't have any detectable amount.

The autofill was turned off, the overflow capped at the pool, pool equipment turned off. Pool did not lose any significant amount of water! My curb was dry for once! PB drilled two small holes into the overflow drain section by the drain that goes to the street. The overflow kept siphoning water out even when it was below the set level. The holes help break the siphon and prevent from losing water when not needed. So far so good!

Just wanted to update in case anyone ran into a similar issue later!