Sand filter changed @ start of season ? HIGH PRESSURE @24 PSI FROM START
I noticed at start of season I'm building pressure on both recirculate and filter positions. I noticed when I started up the filter I backwashed so I could fill water in the sand filter. Then I rinsed then I went to filter mode, the pressure started at 24 psi. on the new guage. I thought from last season my guage was faulty not the case. Any ideas on why? I have A 18 x 36 inground pool with heater. When A filter needs to be backwashed the water flow is weak this is what happens on both filter and recirculate positions. But the flow is great at the start of either position, just as it runs it get a weak flow to the pool.
Re: Sand filter changed @ start of season ? HIGH PRESSURE @24 PSI FROM START
What was the pressure doing last year? Wondering how much it changed. Also what size filter and pump combination is in the system? 24 psi does sound bit high. I think typically something 15 or lower would be normal right after a backwash.
Al
Re: Sand filter changed @ start of season ? HIGH PRESSURE @24 PSI FROM START
Quote:
Originally Posted by
Poconos
What was the pressure doing last year? Wondering how much it changed. Also what size filter and pump combination is in the system? 24 psi does sound bit high. I think typically something 15 or lower would be normal right after a backwash.
Al
Last year it was the same started around 24 and before it could build up to 10 from where it started the flow to the pool was so slow my chemicals where not being moved through the pool and I had a fit keeping it clean. Also I checked the laterals when I changed the sand no cracks or stopped up. I just don't know.
Re: Sand filter changed @ start of season ? HIGH PRESSURE @24 PSI FROM START
What about the pump and filter sizes? Almost sounds like the pump is way too big for the filter.
Al
Re: Sand filter changed @ start of season ? HIGH PRESSURE @24 PSI FROM START
300 bls. of sand pretty good size. 1h.p. motor pump 8 yrs old
Re: Sand filter changed @ start of season ? HIGH PRESSURE @24 PSI FROM START
Bumping this thread back up to see if we can help this new member.
Re: Sand filter changed @ start of season ? HIGH PRESSURE @24 PSI FROM START
Oops, sorry I missed this. The forum software is set to mark forums as 'read' when one logs off. I get on for only a couple minutes at times and of course when I get out everything now looks like I read it. Enough of that. If anyone doesn;t get a timely reply simply add another post to bump it to the top of the list. Posters do this all the time.
OK, on to the problem. My next logical question is what does the pressure look like on Backwash and Waste? Waste simply dumps the output of the pump to the waste or discharge line. You've got to try and isolate where the restriction lies. Sure sounds like something in the return piping. Also try taking the eyeballs out and see if the pressure drops. On my pool I bored out the eyeballs to the largest diameter I could just to cut the restrictions.
Al
Re: Sand filter changed @ start of season ? HIGH PRESSURE @24 PSI FROM START
Quote:
Originally Posted by
timmygreene
Last year it was the same started around 24 and before it could build up to 10 from where it started the flow to the pool was so slow my chemicals where not being moved through the pool and I had a fit keeping it clean. Also I checked the laterals when I changed the sand no cracks or stopped up. I just don't know.
If I am reading your reply correctly, I think the problem is that you are waiting way too long to backwash the filter. Pumps have a maximum head that they can produce flow, if you start at 24 PSI but do not backwash until 34 PSI, the pump is experiencing at least 78 feet of head. Dead head for most pumps is less than 80 feet of head and some as low as 60 feet. I would backwash before the PSI reads 30 and preferably before 28.
As Poconos points out, there may be ways to reduce the 24 PSI as well but that depends on your plumbing setup.
What is your pump model?
Distance between the equipment and pool?
Pipe diameter?
Number of runs for suction and return lines?
Number of return eyeballs?
Re: Sand filter changed @ start of season ? HIGH PRESSURE @24 PSI FROM START
Hi Mark,
I think I'm reading his post as the pressure is at 24 right after a backwash and also in recirculate mode. I also have a 300# filter and 1 HP superpump and the pressure after a BW usually runs in the 12-14 psi range. If I remember right, with flow totally blocked, multiport in closed position, the max pressure I can hit is around 30, maybe a little higher. Personally I never follow the rule of waiting for a 10 psi increase to BW, usually just 3-4 or so unless I'm doing the DE trick.
Al
Edit: reading the first post again I have another question. Timmy you mention the flow is OK at first then drops. How about the pressure immediately after BW?
