New to pool maintenance in San Diego, CA - need to partially drain pool due to high CYA

[RedCat11156]

Hi, we're taking over our pool maintenance as our pool guy just retired--without much notice. We've lived here only a couple of years and this is our first pool, so we don't know anything. Ordered a test kit, but in the meantime I had our local pool supply store test the water and our CYA is super high(100) (pool guy used 2 tabs/week). I plan to drain 50% of the water next week so I can use liquid bleach from here on out.
FAC= 3; TAC=3; CH= 270; CYA=100; TA=100; PH=7.5

Where should I look or post on this forum to answer this question:
**Should I do anything special (during drain/refill) because of our copper plumbing?**

I bought a 1/4 HP submersible pump and plan to not add any chlorine (will test) until the FAC is 0 as mandated by our local gov to drain safely into the storm drain. The local rules are: water dechlorinated, pH of 7-8, no algae.

The reason I ask about metal is that shortly after we moved in, our pool maintenance guy (holdover from last owner) wanted to drain and refill due to high CYA and a few days after the refill we had dark, dark brown water. He said it was because of metal in the water and we don't want this to happen again. That was 2 years ago. I honestly suspect he retired at this very moment so he wouldn't have to deal with draining our pool again!

Thanks!

 

[mknauss]

Welcome to the forum!
I would wait until you have your own test kit before draining. Pool store tests are notoriously not accurate.
What test kit did you order?
I am amused by the requirements of no chlorine and no algae for draining. That is typically nearly impossible. Who test for the chlorine in the effluent? Even drinking water has measurable chlorine in it.
I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Pool School eBook.

 

[mknauss]

**Should I do anything special (during drain/refill) because of our copper plumbing?**

No. The copper plumbing is no issue as long as you keep you pH above 7.2

Also, the brown water last refill. That implies iron in the water. Do you have iron staining on your fixtures in the home? Or do you have a water softener?

 

[RedCat11156]

Re: Chlorine at 0, gotcha. No one tests the effluent. I just want to follow the rules.

We don't have a water softener or iron staining (except around one old fixture in the kitchen that I suspect is not stainless). Hmm. I didn't mention this but the pool supply test showed 2500 ppb phosphates.

It might be that the ph was lower than 7.2. Pool guy said he has to add soda ash every now and again to keep up the ph. I ordered K-2006 test kit.

Thank you for your recommendations and the quick responses.

 

[RedCat11156]

Oh, I have an old and possibly deteriorating heater that is still connected to the plumbing system. I'm not sure how to remove this. Going to read the links you provided now.

 

[mknauss]

If the pool was chlorinated with trichlor (pucks) then there is a good chance the pH was quite low most of the time, why they used soda ash.
The heater most likely is dissolved (and be wary of your copper plumbing) due to the low pH. Just remove it and connect the pipes.

Also phosphates are of no concern. If that was a pool store test it was most likely wrong anyway. Phosphates are algae food. TFPC eradicates algae, so phosphates do not matter.

 

[RedCat11156]

Thank you!

 

[Rancho Cost-a-Lotta]

Oh, I have an old and possibly deteriorating heater that is still connected to the plumbing system. I'm not sure how to remove this. Going to read the links you provided now.

If you post some pics, I'm sure someone will be able to guide you in plumbing in heater bypass.

 

[RedCat11156]

I showed some photos to a guy at another pool supply store and he saw that there is some rebar coming through the plaster in the pool. I showed photos of the heater and he thinks it's a good idea to remove it, but that the iron is clearly coming from the rebar. So. I am waiting for my water test kit to arrive, but this pool store also tested CYA as over 120ppm, so I think that a full drain of the pool is likely. I am guessing that if I take the water below the rebar spot it will oxidize and introduce more rust into my water post refill. I can plan to deal with that, we can't, unfortunately, afford to repair the rebar at this time. Hoping I can deal with it before brown water appears. I will order copper and iron test strips. Thanks everyone! Side note, I can see how/where to bypass my heater (20190601_104749.jpg) but don't have the diy chops to feel comfortable cutting and attaching pvc pipes, so I will probably hire someone to do the bypass for me.