Yes, after no rain for 90 days and we received about 1/2 inch

[Mark R]

Not a lot, but got me wondering how this would effect my chemical balance.

Number prior to rain:
FC 4
CC 0
Cya 70
CH 350
PH 7.4/6 from basic daily test kit
TA is around 120

So how does rain effect my pool water because before I know it we will have the summer deluge of rain and want to be ready. No run off in my pool, right from the sky into pool. Also, my CYA is high enough for the heat ? Should I expect to be adding at least at least a few gallon a week of bleach 8.25% due to my full day of sun on the pool and solar system in full force by the beginning of April.

Does it throw everything off balance, especially when the outside temp will be 100+ and the pool water will be 80 very soon ?

Also I went to Lowe's and they only carry MA
that is less then 15 %. Pool store has it at 34%, so I bought that. Not that much more expensive.


Thank you for all your help so far this year. Like to plan ahead.

Mark

 

[Smykowski]

In a properly maintained pool, rain has very little effect.
I can't give numbers because I don't know your pool's dimensions, but as a percentage of the total volume, a half inch is nothing. I purposefully divert rainwater from my roof into my pool and I have no issues.

70 for CYA is fine for the heat, but you need to keep your FC a little higher. 5 is your bare minimum, and you should never let it fall below that.

 

[pwrstrk]

For a CYA of 70 your FC level should never fall below 5. At 70 ppm for a non SWG is a little high, but it is manageable. Now if you have to SLAM because FC has fallen below min, that's where your going to feel the high CYA level by the amount of bleach you will need to do the SLAM process. http://www.troublefreepool.com/content/128-chlorine-cya-chart-slam-shock
Rain water will have little effect on your chemistry as long as everything is in range.

As to how much bleach you will go thru in a week, I have no idea. Contributing factors on that will be water temp,how much sun the pool gets, organics, bather load. That's where testing and keeping your FC level in range come into play.

 

[Isaac-1]

Just to add in at 70 your CYA is a little higher than we ever suggest for a non SWG pool, 50 - 60 ppm is as high as we suggest for sun belt pools. Generally the only way to practically lower CYA is through water replacement as it does not evaporate with water, however since yours is only slightly over the suggested range you can also probably just give it time and it will naturally lower as CYA does break down over time, just at a very low rate, somewhere in the ballpark of 1-3% per month depending on temperature, chlorine level, etc. In most areas splash out, rain fall, etc. will mask this natural break down rate it is so low. Again also your FC level is a bit low for your current CYA, I would suggest taking some time and reading over the Pool School link at the top right of this page (assuming your reading the standard web page, not tapatalk mobile version).

Ike

 

[Patrick_B]

A rain of 1/2" should have so little effect on things it will be barely noticible at all. You'll have to have a significant rain, with lots of diversion into the pool to ever see much of a change. No worries.

 

[msgtdan]

Rain water is TA and CH free so can help lower those if your fill water is high. I use the spring rains to refill my pool after winter drawdown so I keep my CH and TA a reasonable levels. I know of a couple people on here that divert their gutter downspouts to the pool for the same reason.

 

[Mark R]

Thank you

I'll retest my CYA, after a total refill I only used 3lbs of the Wal-Mart stabilizer so it might even be lower then 70. It's been just about a week, so I should have more accurate results now. I added 2lbs through a sock when I refilled, then waited 2 weeks and added another pound last week. I think the container said "HTH" stabilizer, 4lb plastic container with granular CYA.

That CYA test seems the hardest most subjected part of all my tests.

 

[pwrstrk]

No problem !?