New member introduction and questions

[Trespassers W]

Hi All,

I have been reading this forum for some time now, a lot of useful information! Finally I am ready to post.

We moved into our new house with IG 32k gal pool a couple of weeks ago and finally I am getting more time to take proper care of the pool (so far have only been adding some bleach).

Previous owners used pool maintenance company, according to the logs I was able to get they were just putting trichlor tablets + adjusting pH as needed. Being concerned about CYA levels, I immediately removed the tablets from the pool and switched to liquid bleach. About 1 week ago I added bleach to raise FC to ~ 18 and let it drift down to 4.0. Since then I have been cleaning filter cartridges every 2-3 days as the pressure quickly raises to 28-30.

Below are yesterday's test results:

FC 1.0
CC 0
pH 7.9
TA 180
CH 975
CYA ~ 200 (had to do 2x dilution to make it readable)

The water looks nice and clear. I added bleach and muriatic acid as suggested by the pool calculator to raise FC to 4.0 ppm and lower pH to 7.4.

Now to the questions:
1) Given the CH and CYA levels, I understand that water needs to be replaced, but with outside temperatures around 95 this might not be feasible. Can I wait for a couple of months or should I start gradually replacing water?
2) I reprogrammed pump run time from 13 to 8 hours per day. Water stays clear. Any suggestions on the run time (more/less/stay the same)?
3) What could be the reason for raising filter pressure? Do I need to keep adding chlorine and cleaning filter or is this a sign of the cartridges going bad?

Thank you in advance for all answers!

 

[Richard320]

1) If the water is otherwise clear, you can defer the draining, but you'll need to maintain a minimum FC adequate for your CYA level, which is somewhere around 15 to 20.
2) Keep lowering run time until the water starts to lose some sparkle, and then raise it back up.
3) The lengthy one. Odds are, because of your high CYA and low FC, you do have algae, it just hasn't exploded into a full-blown bloom to where the water gets cloudy and/or green. Essentially, I think you're in a precarious stalemate. You kill the algae at the same rate it reproduces, and the filter loads up with the bleached dead carcasses.

The cure is the Shock Level And Maintain Process. Unfortunately, with the CYA so high, it's nearly impossible. Which leaves you at option two: a partial drain. With the CYA so high, you'll be able to make rapid progress doing a series of partial drains. For the sake of argument and simple math, let's say the CYA is 240 and the average pool depth is 40 inches. Draining 10" of water is 25%, which will put the CYA down to 180. Draining another 10" a few days later will take CYA down to 135. Obviously, the more you drain at each go around, the faster the CYA drops. The only real limits are leaving enough water in the pool to prevent the plaster shell from floating (if groundwater is close to the surface) and how fast you can refill overnight.

Once the CYA level is down to a realistic number, then the SLAM will eradicate any algae spores and the water will sparkle and the filter won't clog so fast.

 

[Trespassers W]

Thank you, Richard! Partial drain/refill while keeping FC levels seems to be the way to go at this point. Could you please provide more details on this:

The only real limits are leaving enough water in the pool to prevent the plaster shell from floating (if groundwater is close to the surface) and how fast you can refill overnight.

What is the "shell floating"? Also, how one could find info about local groundwater levels?

 

[Richard320]

This is what a floating pool looks like http://www.myfoxtampabay.com/story/...n-disbelief-after-pool-pops-out-of-the-ground

Look around. Are there marshes or swamps nearby? Are there creeks nearby and running? Sometimes the county or state keeps track of well depths.

 

[Trespassers W]

This is what a floating pool looks like http://www.myfoxtampabay.com/story/...n-disbelief-after-pool-pops-out-of-the-ground

Wow, this looks nasty!

Look around. Are there marshes or swamps nearby? Are there creeks nearby and running? Sometimes the county or state keeps track of well depths.

No, it is pretty dry around here, no swamps for sure. I will check local websites, I think I remember seeing some water level maps on the city government website.