Recent content by rephil

I had to drain the pool several times, and a couple times I couldn't drain faster than the rain was filling it and it overflowed, getting runoff/dirt into it. It was a brown/green mess when the rain stopped. My post-Harvey readings were almost all 0, but pH was somehow still 7.6. NO stores...

Thanks! I can't derive the formula, but that makes sense. At a CYA of 50 the Daily Target range is 2-4ppm higher than the minimum, which makes sense given most people see a 3ppm daily drop in FC. The difference gets larger at higher CYA levels, but at CYA of 100 or below it seems to stay...

Yes, I know. But that's not the question. Why is the "Daily Target" a 3ppm window for any "now" CYA level? For a CYA of 20 it is 3-5. For 500 it is 51-53.

Not sure I follow this logic. On PoolMath you can put the CYA at any number, try 500, and the "Daily Target" is always a 3ppm window (51 to 53 in that case). That tells me it's not based on a percentage of CYA.

This is good info, didn't know this stuff. I also looked at PoolMath and for any given CYA level the "Daily Target" is always a 3ppm window. For me it's 6-8, but could be 7-9 or 15-17, etc. What's the logic/science behind that? I'm still leaning towards an every-other-day amount of bleach...

Makes sense. Conveniently I am losing the equivalent of about half a gallon of bleach per day. Just opening a gallon jug and dumping the whole thing every other day would be 50% less work.

My CYA is about 50. Maintaining somewhere between 6-8 FC, with about a 3ppm loss per day (full sun in TX). I've seen several posts asking if certain levels of FC are too high, and the response is always that you can bring FC up to shock level and still swim safely. So if that is true, my...

I think a sparkling pool is what everyone on this forum is going for.

Actually it says most pools require 4 hours or less, not 2, see page 12. In fact, the first conclusion is that "a few hours" is recommended (page 11). They suggest 2 hours as the minimum, see page 13. Correct. It means the turnover amount within those 2 hours would be somewhat similar across...

Imagine a bell curve. The middle is average (also median). The 25% on either side is "most pools", making up a total of 50%. So yes, when they say 2 hours they are effectively talking about an average. At this point i feel like i'm being trolled, but i'll say it again. When a pump runs, it...

They aren't suggesting an equal run time in the study. It's an AVERAGE minimum suggested based on their findings across many pools. It's not a magic number either. I don't know how this is hard to grasp. A pump moves water. That's ALL it does. Pump run time = water movement = turnover. A = B...

You can keep calling it run time...but it's run time of the pump. And the pump moves water. In your example, if your was a GPM of 1 instead of 35, it would take longer. Water has to move through a SWG (or an inline chlorinator) to be chlorinated. If it takes 100 gallons or 10k gallons of...

It's splitting hairs, but what they are talking about is still turnover. There's an amount of water, slightly different for each pool, that must flow through the system in order to reach desired quality. It can't be based only on run time since every system and GPM will vary. However for most...

"studies have shown that a typical pool really only needs about 4 hours of run time for proper chlorination, circulation and cleaning" Based on what? I'm not challenging it, but is that not based on how much water needs to be filtered, mixed, run through a SWG or Chlorinator, etc? Effectively...