Opening Numbers

[SUNNYDAYS]

Update

Cl 3.0
CC 0
TC 3.0
PH 7.4
CH 180
CYA 60
TA 60


I was able to get the CYA down from 100 to 60 will continues to lower it a little more with vaccuum to waste and refill with fresh water.

What do you think about the numbers I know I need to get the chlorine up.

[rilesworld]

Looks good, but you may want to raise your TA a bit as well. Maybe at least in the 80-100 range.

[chem geek]

Your numbers look fine except, as you noted, the FC should be closer to 6 ppm or certainly an absolute minimum of 4 ppm. This is to prevent green algae. If you are in an environment that frequently gets mustard/yellow algae, then an even higher FC of 9-10 would be required, but only a few pools seem to need that.

Of course, keep working on dilution to get your CYA down even lower so you can run with lower FC levels.

I assume that since you are using bleach or chlorinating liquid that your pH is relatively stable even with your low TA (which is fine unless you have a pH issue). I also assume that with your vinyl pool you have no tile line with grout or any plaster/gunite/grout exposed to the pool water whatsoever (just making sure).

If you are using bleach or chlorinating liquid for chlorine, then please make sure you add it VERY slowly over a return at the deep end so that it can dilute in the return stream and flow towards the floor drain and the skimmer on the opposite side (if that's how it's set up). There is a very experienced installer of pools on another site who is sure that every single vinyl replacement has been with someone using a liquid from of chlorine and he encourages the use of (expensive) lithium hypochlorite instead (or pre-mixed Cal-Hypo in a bucket). It is true that concentrated chlorine is more dense than water so will migrate towards the bottom if you just dump it in quickly, but when diluted (hitting the return flow, for example) it should lower in density close to water and not "settle". Until I get this sorted out, you should be very careful -- and could even pre-dilute the liquid chlorine in a bucket of water and pour that slowly to be even more safe. Also, pouring very slowly into the skimmer might be OK as another alternative.

At some point, I'll do some experiments in my pool with these two chlorine sources and see if I can measure the dispersion rate of the chlorine from one end to the other. The Lithium Hypochlorite probably is safer not only because it dilutes very quickly but also because it can be applied over the large surface of the pool and not in one place (though on a windy day I'm not sure how well that would work out). However, I am not yet convinced that there is no safe way to add bleach or chlorinating liquid. My hunch is that it is the improper application that is the problem, but we'll see (I've been wrong before, of course).

Richard