First water test shows way out of range, any suggestions?

[BillT2]

Hi all, I just tested my water and was hoping for some input from people who know more than me. I have no prior pool experience but recently moved into a house with a pool. I ordered a test kit etc, and by the time I’ve gotten around to testing the water, it’s been at least two weeks since any adjustments were made - the pool was previously being maintained by a company. I did check the FC a week or two ago and it was in normal ranges, but I’m just now doing the other tests and hadn’t added any chlorine since then. Pool water looks clear to me, though it’s been raining several days so it’s been hard to get a great look.

The numbers though are pretty far from ideal - I did each test twice and got the same results:

FC - 0.5-1.0
TC - 0.5-1.0
pH - 8.2+ (darker than 8.2)
TA - 170 (edited - originally tested at 400 due to drops being too small)
CH - 750
CYA - 150+ (did 50/50 water dilution and still got 80-90)

Just now able to look into how to address this - I am guessing the suggestion will be to replace water before trying to balance anything? If so, how much would you recommend replacing and what would be the best method to do this? Or any other input? Thanks!

19k gal IG Plaster, Filter Pump: Pentair VS 3050 variable speed, Filter: Pentair Quad DE 80, Rainbow 320 in-line chlorinator, TF-100

 

[Jimrahbe]

Bill,

Welcome to TFP.. A great place to learn how to maintain your own pool.

With a CYA of 150, I would replace most of the water.. I'd shoot for at least 75% of it.

A TA of 410 sounds odd to me.. But that is the least of your worries. I'd test your house water for CH and TA and see what they are for reference.

Are you using a Speed-Stir or similar device to stir the water as you add drops???

With all this rain you might want to check out your water table before draining at all.. It does not happen often, but even concrete pools can float out of the ground if there is a lot of ground water..

Thanks,

Jim R.

 

[BillT2]

Thanks Jim - I will do that on the house water - and yes I am using a magnetic stirrer. There's a good slope here if I'm going to drain - when saying replace 75%, would that be all at once, like pump 75% out and refill immediately?

 

[Jimrahbe]

Bill,

That is what I would do... I'd check with the City first.. A lot of cities will only charge you for the water and not the sewer if you tell them you are going to fill a pool. It can't hurt to ask.

Thanks

Jim R.

 

[BillT2]

Thanks that makes sense. I just checked the water at the hose bib near the pool and got the following, and I'll have to check the water at pool filler when the level is down.

Hose bib water: pH 8.2, CH 125, TA 180 (edited)

Is the TA being so high going to be a problem? The final dropper for the TA test in my kit is a little funny, the droplet size seems very small so not sure if a dropper issue is ever a factor? I am using the amounts included with the TF-100 kit

 

[an1vrsy]

Hey @BillT2 Have you seen the extended test kit directions for TA? Here is a note from those directions

• Sometimes a static electric charge can build up on the R-0009 dropper bottle tip, causing the drops to be smaller than usual and making the test read higher than actual. You can prevent this by wipping the tip of the dropper bottle with a damp cloth or tissue before you start and after each drop.

here is the link to the article

 

[BillT2]

Thanks @an1vrsy I had seen the note on that but wasn't sure what effect it was supposed to have. I had not seen the whole article though, and I just retested pool water at 170 TA and tap water at 180 - so that seems more reasonable and drop sizes were the same as other bottles this time. Yes my inaccurate tests all had tiny droplets it seemed like at the beginning so, makes sense now

 

[BillT2]

So I am realizing now that the coping around the pool is most likely in need of repair/replacement, the stone coping is separated from the mortar underneath all along the pool, several stones are loose, and the spa in particular is loose all around. My understanding is the pool would need to be drained for this, and soonest I can get on someone's schedule is in the fall.

Given this, should I just make do with the water until that time? Or should I replace something more like 25% and balance from there? Since all will be replaced when the pool is drained later in the year...here are my numbers again:
FC - 0.5-1.0
TC - 0.5-1.0
pH - 8.2+ (darker than 8.2)
TA - 170
CH - 750
CYA - around 200 (did 1/2 and 1/4 dilution)

I also added some chlorine back in today since I may not be draining it yet

 

[an1vrsy]

I am not a coping sub or in the trades. I can say that my tilesetters also set my coping so you might be able to obtain more estimates and scheduling by looking for tile setters.

Related to can you maintain and sanitize a pool with CYA at or above 150 ppm. Someone way smarter than me will have to advise you. I say unless water is restricted or extremely expensive drain it now.