First of all, let me warn everyone reading this that i tend to be an extreme over-analyzer. I'm sure that is the case again here, but I'd like to know what others think about my analysis, nevertheless.
My pump is currently running non-stop, because the water was cloudy when I took off the pool cover. It honestly looked clear to me, and I had made a couple of FC checks and chlorine consumption is as expected this time of year (around 1 PPM/day with water temperature in upper 70s), but I had obviously forgotten what the water is supposed to look like. My wife came out and said she thought it looked a little murky, and she was so right. I looked back at a photo from last summer and was shocked (and mad at myself for thinking my water was clear)! So I turned on the pump and let it run. It has now been through 3 backwashes (at 16-20 PSI when starting at 11 PSI clean with DE)! I plan to run it until there is no increase in PSI for 12 hours, since it has occurred to me that one of the best indicators of water clarity is no increase in filter pressure. I am often asking myself, "Is the water really as clear as it could (should) be?" Now it seems that since I can't trust my eyes, I can rely on my pressure gauge.
Experience has led me to the conclusion that 4 hours per day is sufficient to keep my pool looking good. In years past, I have broken this up into 4 1-hour cycles for two reasons:
1) to maximize skimming effectiveness
2) to maximize the effect of heat transfer
Now i am considering just 1 4-hour cycle of pump run time for two (related) reasons:
1) I can observe PSI at the beginning and end to confirm that there is no change in PSI
2) Overall filtering efficiency may increase? (question explained below)
By "overall filtering efficiency" I mean total amount of debris filtered out in 4 hours. I am picturing this as a definite integral of filtering rate over time. It is clear (and logical) that filtering rate is dependent on pressure and flow rate, which are inversely proportional (sort of). Since I learned from a previous post that flow rate decreases more slowly than pressure increases, it seems a moderate increase in pressure will also increase filtering rate. I have noticed that when the pump turns on, pressure is often 1-1.5 PSI less than it was at the end of the previous run cycle. (This makes no sense to me, but i attribute it to redistribution of filtering media when pump shuts off and then is turned back on.) Hence, the area of the integral I am picturing would be greater as 1 integral over 4 hours than 4 integrals over 1 hour each. Does that make sense?
If you actually read this far without giving up because I am a nut case, thank you. Do you have any thoughts regarding my theories? Are they valid, useless in practice, both, or neither?
My pump is currently running non-stop, because the water was cloudy when I took off the pool cover. It honestly looked clear to me, and I had made a couple of FC checks and chlorine consumption is as expected this time of year (around 1 PPM/day with water temperature in upper 70s), but I had obviously forgotten what the water is supposed to look like. My wife came out and said she thought it looked a little murky, and she was so right. I looked back at a photo from last summer and was shocked (and mad at myself for thinking my water was clear)! So I turned on the pump and let it run. It has now been through 3 backwashes (at 16-20 PSI when starting at 11 PSI clean with DE)! I plan to run it until there is no increase in PSI for 12 hours, since it has occurred to me that one of the best indicators of water clarity is no increase in filter pressure. I am often asking myself, "Is the water really as clear as it could (should) be?" Now it seems that since I can't trust my eyes, I can rely on my pressure gauge.
Experience has led me to the conclusion that 4 hours per day is sufficient to keep my pool looking good. In years past, I have broken this up into 4 1-hour cycles for two reasons:
1) to maximize skimming effectiveness
2) to maximize the effect of heat transfer
Now i am considering just 1 4-hour cycle of pump run time for two (related) reasons:
1) I can observe PSI at the beginning and end to confirm that there is no change in PSI
2) Overall filtering efficiency may increase? (question explained below)
By "overall filtering efficiency" I mean total amount of debris filtered out in 4 hours. I am picturing this as a definite integral of filtering rate over time. It is clear (and logical) that filtering rate is dependent on pressure and flow rate, which are inversely proportional (sort of). Since I learned from a previous post that flow rate decreases more slowly than pressure increases, it seems a moderate increase in pressure will also increase filtering rate. I have noticed that when the pump turns on, pressure is often 1-1.5 PSI less than it was at the end of the previous run cycle. (This makes no sense to me, but i attribute it to redistribution of filtering media when pump shuts off and then is turned back on.) Hence, the area of the integral I am picturing would be greater as 1 integral over 4 hours than 4 integrals over 1 hour each. Does that make sense?
If you actually read this far without giving up because I am a nut case, thank you. Do you have any thoughts regarding my theories? Are they valid, useless in practice, both, or neither?
