11:30 am today and fc is 19!!! Wow.
Added DE -psi 13
Cya 28
PH 7.2
Ordered new multivalve
Added DE -psi 13
Cya 28
PH 7.2
Ordered new multivalve
What to fix first?
- Thread starter wowens
- Start date
I know that no one is replying to your posts, but you're doing good and although we're not replying, we're still watching and following.
iam4iam
LifeTime Supporter
Wowens has been out of town this week and I have been monitoring/maintaining the SLAM on her pool. Finally seeing progress daily! Yesterday I could actually see the perimeter of the hopper! She essentially has a new filter, having replaced multiport valve, sand, and the lateral assembly, which supposedly had a cracked lateral, although I looked at the old one and couldn't tell. I don't see how this could happen, but the symptom was sand in pump basket, indicating that sand was in pool. Other possible logical cause was spider gasket, which was replaced with (or part of) the multiport valve. I don't want to question any of those replacements at this point, though. I mention them only for informational purposes. I do have 2 questions, though:
1) CC has been near 0 for several days now, seeming to indicate that all organic matter has been killed, and now it is just a matter of waiting for the filter to clear the water (which is happening faster since I've been adding DE after each backwash--could be happening even faster if I were able to stay at her house and monitor PSI more closely). I know the "M" in SLAM means until all 3 requirements are met, and I haven't been able to perform an OCLT yet, but I suspect it is low (Isn't OCL proportional to CC?) and that the vast majority (if not all) of the chlorine loss at this point is from sunlight. How important is requirement 3 ("Water is clear") to end the SLAM? I'd sure like to save her some $ at this point if possible!!!
2) Upon returning to her house each day, PSI is more than double the clean filter PSI, and pump has lost prime. This seems counterintuitive, but after seeing this happen 3 consecutive days, it certainly appears that the massive increase in PSI is the cause for the loss of prime. Can you explain this? It seems like high pressure would make it easier for the pump to prime! It seems like pump would have the most difficulty priming with filter set to "recycle," since there is less resistance to allow pump suck water in faster than it's getting pushed out. Pump always primes quickly after backwashing (actually primes during backwash/rinse and maintains prime when returning to filter setting, which is not what I remember being the case on my filter, which allows air in whenever I change the multiport setting, which leads to question 3, which I hadn't planned to ask)
3) Should changing multiport from backwash to rinse to filter allow air in?
1) CC has been near 0 for several days now, seeming to indicate that all organic matter has been killed, and now it is just a matter of waiting for the filter to clear the water (which is happening faster since I've been adding DE after each backwash--could be happening even faster if I were able to stay at her house and monitor PSI more closely). I know the "M" in SLAM means until all 3 requirements are met, and I haven't been able to perform an OCLT yet, but I suspect it is low (Isn't OCL proportional to CC?) and that the vast majority (if not all) of the chlorine loss at this point is from sunlight. How important is requirement 3 ("Water is clear") to end the SLAM? I'd sure like to save her some $ at this point if possible!!!
2) Upon returning to her house each day, PSI is more than double the clean filter PSI, and pump has lost prime. This seems counterintuitive, but after seeing this happen 3 consecutive days, it certainly appears that the massive increase in PSI is the cause for the loss of prime. Can you explain this? It seems like high pressure would make it easier for the pump to prime! It seems like pump would have the most difficulty priming with filter set to "recycle," since there is less resistance to allow pump suck water in faster than it's getting pushed out. Pump always primes quickly after backwashing (actually primes during backwash/rinse and maintains prime when returning to filter setting, which is not what I remember being the case on my filter, which allows air in whenever I change the multiport setting, which leads to question 3, which I hadn't planned to ask)
3) Should changing multiport from backwash to rinse to filter allow air in?
1) OCL isn't really proportional to CC. A lot of pools have zero CC throughout the entire SLAM process and can't pass the OCLT.
2) High discharge pressure affects priming ability a little because the total flow is diminished and therefore the pump isn't able to "suck" as efficiently as it should. However, closing off a valve on the suction of the pump when switching positions on the multiport will prevent losing prime in the first place.
3) Yes, it certainly can. When you press down on the handle it opens all ports simultaneously and therefore air can enter the filter through the waste port and since the pool is lower than the pump water will flow backwards toward the pool pulling the air with it and emptying the pump of water. Therefore losing prime.
2) High discharge pressure affects priming ability a little because the total flow is diminished and therefore the pump isn't able to "suck" as efficiently as it should. However, closing off a valve on the suction of the pump when switching positions on the multiport will prevent losing prime in the first place.
3) Yes, it certainly can. When you press down on the handle it opens all ports simultaneously and therefore air can enter the filter through the waste port and since the pool is lower than the pump water will flow backwards toward the pool pulling the air with it and emptying the pump of water. Therefore losing prime.
iam4iam
LifeTime Supporter
THANKS for the quick reply!
So can I allow FC to return to normal if pool passes OCLT? (Or is that unlikely to happen before pool is clear anyway? By "clear" I mean CLEAR!)
So can I allow FC to return to normal if pool passes OCLT? (Or is that unlikely to happen before pool is clear anyway? By "clear" I mean CLEAR!)
Prime is not lost when switching multiport positions. It was already lost (apparently) due to pressure increase. Pump is fully primed after backwashing and returning to filter position. Can increased pressure cause pump to lose prime? By the way, how do you "close off a valve on the suction of the pump"?
Her waste line is a long hose at ground level which is still full after backwash/rinse, so I suppose this would explain lack of air when I switch from backwash --> rinse --> filter.
Part of the OCLT is that the water is clear, so we don't even suggest running the OCLT until that happens.
The pressure increasing while the pump is running and primed can't cause the pump to lose prime. Introducing air to the pump suction is the only thing that causes a pump to lose prime. Closing off a valve on the discharge won't cause it to lose prime. It won't pump any water, but it'll still be primed (until the water starts boiling).
A lot of systems have valves on the suction and discharge of the pump somewhere. Hers may not have them and therefore closing one won't be an option.
She probably doesn't have a vented sight glass so you're correct about it not allowing air into the system in this case.
The pressure increasing while the pump is running and primed can't cause the pump to lose prime. Introducing air to the pump suction is the only thing that causes a pump to lose prime. Closing off a valve on the discharge won't cause it to lose prime. It won't pump any water, but it'll still be primed (until the water starts boiling).
A lot of systems have valves on the suction and discharge of the pump somewhere. Hers may not have them and therefore closing one won't be an option.
She probably doesn't have a vented sight glass so you're correct about it not allowing air into the system in this case.
Too many people end their SLAM early and algae returns, often because they forget about the "M" part for maintaining the elevated chlorine level. Technically if you did an OCLT and it showed low chlorine loss, the water is cloudy and not green with no visible algae, and your CC is low then you are right that it is most likely that primarily filtration is needed to clear the pool. It's simpler to give advice that covers the situations where there are still significant organics to oxidize or algae to kill, especially because some pools have poor circulation so when cloudy one doesn't see what's going on at the bottom of the pool.
iam4iam
LifeTime Supporter
Thanks, Richard. Will do OCLT tonight. I suspect it will be low. Here is a picture of the vacuum at the bottom of the pool in the hopper. The water is definitely still not completely clear, but we've come a long way!
I'll post a few more pictures of the progress when I get home to my computer.
Sent from my XT1045 using Tapatalk
Sent from my XT1045 using Tapatalk
iam4iam
LifeTime Supporter
What in the world kind of filter was that person using??? That clarity was the result of 4 days of work?? Granted, I'm only stopping by the wowens' house once a day, so the clarifying process could be happening faster, but WOW! Those are some amazing pictures! Not hard to believe bleach did that, of course, but hard to believe the filter cleared the water that fast!!
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She must have a pin hole air leak somewhere then. What I fail to understand even if what you have said is true is how an air leak that isn't significant enough to prevent the pump from priming to begin with would be significant enough for the pump to lose prime. The only possible explanation I can imagine would be water level gradually getting lower in skimmer, causing pump to suck air with the water.
There are a couple of things that made that clearing go faster. First is that you will note that the addition of bleach not only killed the algae, but coagulated it so that much dropped to the bottom so that it could be vacuumed to waste (twice, and brushed once) so I suspect that it was added without the filter running at least initially before the first vacuum-to-waste. Second is that the filter was a DE filter. Nevertheless, even those with sand filters can get faster clearing if they Add DE to a Sand Filter.
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She must have a pin hole air leak somewhere then. What I fail to understand even if what you have said is true is how an air leak that isn't significant enough to prevent the pump from priming to begin with would be significant enough for the pump to lose prime. The only possible explanation I can imagine would be water level gradually getting lower in skimmer, causing pump to suck air with the water.[/QUOTE]
As pressure increases, pump has to work harder to suction thus pulling air more significantly. In new union? In new coupling? In multiport o ring? I assume lots of spots for such a small air leak. Remember I still can not vacuum using a vacuum plate. Not enough suction. May be in pipe line.
I sure have been blessed to have a friend make my pool clear while I was gone. I never thought it possible to see the bottom!
She must have a pin hole air leak somewhere then. What I fail to understand even if what you have said is true is how an air leak that isn't significant enough to prevent the pump from priming to begin with would be significant enough for the pump to lose prime. The only possible explanation I can imagine would be water level gradually getting lower in skimmer, causing pump to suck air with the water.[/QUOTE]
As pressure increases, pump has to work harder to suction thus pulling air more significantly. In new union? In new coupling? In multiport o ring? I assume lots of spots for such a small air leak. Remember I still can not vacuum using a vacuum plate. Not enough suction. May be in pipe line.
I sure have been blessed to have a friend make my pool clear while I was gone. I never thought it possible to see the bottom!
That area behind the hole is a crack. This could be the source of air in line and lack of suction using vacuum plate. You think so?