Odd test results

Apr 6, 2021
24
Litchfield County, Connecticut
Pool Size
15000
Surface
Plaster
Chlorine
Liquid Chlorine
Today:
pH 7.5
TC 1.5
CH 250
TA 60
CYA 0

We opened the pool in April to loads of algae. It is still not clear, we are still brushing green algae daily. In the last two weeks we have been very dedicated to getting the pool finally open, so we have brushed and balanced daily (I even ordered all new reagents in case this was a part of the problem).

Observations:
1. The pH trends up daily. I get it down to 7.2 (with pH Down) and it immediately starts going up.
2. The chlorine! I dump a couple of gallons of 10% LC per day or more. I have never tested the TC higher than 6 (usually 1 CC) - and I test every 2 hours.
3. No CYA. I am on the second hose sock full of Stabilizer in front of the return, shaking it out all day. The first was in May and stayed there until it was low and I added more. I do think I may need to add more more often to keep it full - calculator suggests 5 lbs. I am not there, yet (3+/- lbs added so far).
4. CH was 100 on April 16 (day of opening) and is finally at 250 today. I added Hardness+.
5. TA was 50 at opening, peaked at 130 on 6/18, was 80 on 6/22, and is now back at 60. I plan to add more baking soda to the skimmer basket.

In April: we replaced our heater with the same model (just newer). We have not turned it on, but could this have affected anything? We also added a SWG, but have not turned it on.

We have had to add water every couple of weeks because we have an issue with the controller that causes water to drain directly through the backwash line 24/7. I had a good fix that the pool guys broke (!!!) so I replaced it with a bad fix that slowly leaks a steady trickle of water. We have hard water; could this be part of the balancing problem?

The sides and floor of the pool are stained (I am confident it is iron from our water - my whole house water filter is always a dark orange when I change it out), and we are still getting green puffs of algae from all over the pool. The water is cloudy - we can't see the deep end.

Help.
 
If there was no CYA, then it is not a surprise that FC does not hold under the sun.

However, the bigger question is why CYA is still low after addition.

There is a possibility of ammonia. Please try adding LC (10pm worth) and test 10mins after addition to see if you do get 10ppm or something close. Your pump should be running in those 10 mins. If FC holds, then you need to add CYA to 30ppm and SLAM. If FC drops significantly in those 10mins, then you likely have ammonia problem: you need to add LC every 10 mins until FC starts to hold.
 
I added 3 gallons of 10% LC at 3 pm. I tested at 3:30 pm:
FC 22.5
CC 0.5

What now?
That means you don’t have ammonia problem.

You said that you added 3lb of stabilizer? If your pool is 15k gallon, then that should add 24ppm of CYA. Unless you had absolutely 0 CYA before, safe to assume your CYA will be at least 30.
I suggest you start SLAM according to CYA=30.

The cloudy water indicates algae.
Over the course of the next few days, check CYA. If CYA turns out to be higher, adjust SLAM level accordingly.
 
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