Least amount of RPM's my pump can be set to for an efficient backwash

[MySonJack]

New pool being built here - specs in my signature.

When I backwash, the 2" line goes into a 3" line in a Y about 40-50 away from the pump. I have the pump running at 2400rpm during this backwash process and what we're finding is that the backwash line is connected to other things such as the autocover drain, the pool deck drain... and when I run the backwash for about 3 minutes, the fore mentioned items back up with backwash water. I have to stop the backwash process, allow the lines to catch up and then start the backwash again. Repeat for the next x amount of minutes until the water run clean.

The thinking is, my RPM's are too high to the filter and the system can't support that much water at once. The idea is to back off on the RPM's the backwash system and put it on it's own program button. I thought I might run the backwash initially 2400rpm for 1-2 minutes and then throttle it back.. or maybe 2400 is just too much to begin with. What number is correct?


Thanks in advance,


Brian

 

[mas985]

Specifications for sand filters usually quote 15 GPM/sqft of media. However, if you mostly run at lower RPM then backwash RPM should be at least as much as the filter RPM and probably a bit more. Too low and the dirt may not all come out of the sand.

But 3 minutes should be more than enough to clean the filter. You are better off backwashing for a shorter period of time at a higher RPM than visa versa.

 

[Jimrahbe]

Brian,

The real problem is the plumbing and not the pump speed... What are the chances of fixing the plumbing?

I like your idea.. I would not worry about the actual backwash results and at first, just focus on how much water the current plumbing can handle.. So I would start low, say 1500 RPM and see if that overwhelms the plumbing.. Then keep increasing the speed until it is too much.. After you come up with the highest speed that works, then see how well the backwash works (after your filter gets dirty again..)

Thanks,

Jim R.