New Guy - Testing Results - What next?

[rprice4410]

Hey guys,

I just starting testing with the TF-100 kit and found that my CYA, TA, and PH were all very high. I added Muratic Acid to lower my TA (it was 350). Here are my latest test results:

FC 2.0
CC .5
TA 250
CYA 90
PH 6.8
CH 40

My question is what is the best method to lower the CYA and TA? My PH is already low but my TA is still reading high. Any other advice would be appreciated!

Thanks!

 

[Texas Splash]

Before adding any more chemicals, I would consider lowering the CYA a bit. It's high for a non-salt pool. Otherwise, you'll need to maintain a much higher FC level as you can see on the FC/CYA Levels. Maybe get the CYA down to 50-60 which should be good summer weather levels, then adjust everything else from there. As you may already know, you can only lower CYA by a water exchange, but be careful as to not lower too much at one time if your local water table level is high. @mknauss has a nifty method of exchanging water by continuously exchanging in & out-going water if you're interested.

Once you have new water filled, the TA may be elevated again. To lower TA, follow the Lower Total Alkalinity - Trouble Free Pool page.

 

[DorsalSpine]

I'd double check your CYA reading? Are you using pucks? Do you have a SWG? Your CYA is very high. You are looking at a water change to get that down to a more reasonable number unless you have a SWG. My post overlapped the one above.

 

[Richard320]

A few thoughts:
1) The only reliable way to lower CYA is vy draining and refilling. Since your pool is vinyl, you don't want to drain it lower than a foot left in the shallow end, lest the liner shift. But that is probably enough anyway. So if you intend to lower CYA, stop adding chemicals to the old water, because you're just wasting money.
2) It looks like you overshot the pH reduction., That will happen if you overstate the TA. There is a known issue with brand new test reagents that the R-009 gets static electricity on the tip, which makes the drops smaller than usual, so you use more and think TA is higher than actual. The cure is to wipe the tip off with a damp paper towel between drops. See if the TA reading improves.
3) TA is the last thing you mess with, an only if there's imminent danger from scaling or you tire of daily pH adjustments. Otherwise, just maintain the pH. Each time you add acid to lower pH, TA goes down some. The pH climbs again but the TA will not. Each time you add acid, it should take less than the last time to make the same pH change, and you'll go longer and longer between additions, too. Just be patient.
4) If draining is not an option for whatever reason, things can be maintained with that higher CYA, but it's easier if its lower. If that is your intention, you need to raise FC quite a bit. FC/CYA Levels If you have algae, 90 CYA is too high to SLAM.

 

[rprice4410]

Thanks guys! Yes, I believe the CYA is correct. I have been using the pucks for years. I will retest with TA with the damp cloth method to verify. As for the water exchange, can you explain the best method for doing that? You mentioned that I should drain from the shallow end, is that correct? I'm very interested in getting this down to a manageable level otherwise it appears I will be adding a lot of bleach to maintain my FC level. Plus I have to use the DDP test daily to check versus the FC/PH kit that came with the TF-100.

 

[mknauss]

You can exchange some water without draining.

If you place a low volume sub pump in the deep end and pull water from there while adding water in the shallow end (through a skimmer or into a bucket on a step so you lessen the water disturbance) you can do a fairly efficient exchange. That is assuming the water you are filling with is the same temperature or warmer than your pool water. If your fill water is much cooler than your pool water, then switch it. Add the water to the deep end (hose on bottom) and pull water from the top step.

The location of the pump and fill hose may change if you have salt water, high calcium, etc.
In my pool, with saltwater and high calcium when I drain, I put the pump in the deep end and hose in shallow end. The water in the pool weighs more per unit volume than the fill water from the hose.

Be sure to balance the water out and water in so the pool level stays the same. Also be sure your pool pump is disabled during this process. Once started do not stop until you have exchanged the amount of water you wish.

 

[mknauss]

Plus I have to use the DDP test daily to check versus the FC/PH kit that came with the TF-100.

To be honest, you should always use the FAS-DPD test for FC testing. The OTO (yellow compare test) is just to see if chlorine is in the water, not a reliable way to see what level it is.

 

[rprice4410]

You can exchange some water without draining.

If you place a low volume sub pump in the deep end and pull water from there while adding water in the shallow end (through a skimmer or into a bucket on a step so you lessen the water disturbance) you can do a fairly efficient exchange. That is assuming the water you are filling with is the same temperature or warmer than your pool water. If your fill water is much cooler than your pool water, then switch it. Add the water to the deep end (hose on bottom) and pull water from the top step.

The location of the pump and fill hose may change if you have salt water, high calcium, etc.
In my pool, with saltwater and high calcium when I drain, I put the pump in the deep end and hose in shallow end. The water in the pool weighs more per unit volume than the fill water from the hose.

Be sure to balance the water out and water in so the pool level stays the same. Also be sure your pool pump is disabled during this process. Once started do not stop until you have exchanged the amount of water you wish.

Thanks! I have one other dumb question. If I am doing the water exchange how do you determine how long to perform the exchange? Meaning if I am adding water while also draining the water how will I know when to stop or how long to perform the exchange? Just trying to figure this out based on my pool size and CYA level. Sorry for the dumb questions..

 

[mknauss]

Once you get the in / out balanced, take one of the hoses and fill a 5 gal bucket and time it. Then convert it to Gallons per Minute. Divide that into the volume you want to exchange, and that will give you Minutes to let the process run.