Intex Pool Question - Parallel Pumping?

bocabrad · Apr 8, 2013

Ive got a 15x36 ft Intex inflatable ring circle pool. 2 years ago, last time i had it up i suffered from a nearly useless vaccuum with my 1000GPH cartidge filter. So this year i thought id use my 2nd NIB 1000GPH filter in parallel to get vacuuming done better as well as cut my run time in half. I want to have 1 outlet from pool going to a PVC "T" connector, one filter will be connected to SWC then back into at "T" connector after SWC for return to Single inlet back to pool. And the other side of the "T" will simply have my other 1000 GPH Filter on it going to the "T" again and back to pool.

Am I accomplishing 2000 GPH by this design? Or at least more than 1000? Will this ruin pumps? Is the "T" connector after the filters going to be disrupted by water flowing into itself or continue out unimpeded?

Any help would be great, i have all the materials to make it work, just wanted to run it by you fine folks to see if I'm wasting time and money bf I can return the materials and save up for a larger sand filter down the road.

JasonLion · Apr 8, 2013

It would be simpler and better to get a larger pump!

Still what you are suggesting can be done. The key is that the two pumps must be identical and have identical hose lengths between them and the T joints. If you put the SWG on one side, and not on the other you will unbalance the paths and the two pumps will fight each other and efficiency will go way down. It won't move anything close to twice as much water, but it will do significantly better than a single pump.

Big_kid · Apr 8, 2013

We had several inflatable ring pools and all of them suffered the same trouble as yours. I upgraded to a sand filter and it's been SO much better. Last year when we got the 18x48 Ultra Frame I didn't even bother with the pump that came with it- it's never been plugged in. The pump/filter combo we got was around $200 @ the pool store, but it's well worth it. It is capable of doing the job, it's strong enough to vacuum effectively, and I think it filters better. Ours is a Columbia ½ horsepower 50lb sand filter. It does well for our 7600 gallons, it did just as well but even faster in the smaller pool we had prior to this one.

bocabrad · Apr 9, 2013

I hear you both on the bigger filter suggestion, just had the same filter NIB sitting around and was hoping that I could swing something this way for a few bucks in hoses and PVC. As long as you think i'm not going to ruin anything, I think im going to give it a shot. A little less efficient 2000 is better than 1000 in my book. I have exactly the same lengths of hose so my setup will be an exact match other than the SWC. I'll report back when it gets up and running.

Do you think that if I were to run one filter without shutting off the other "T" to the other filter ever if im going to suffer serious performance issues. I suspect I would.

Thanks again for any advice!

krazykrames · Apr 9, 2013

How about cutting a new return hole in the pool for one of the pumps. I did a quick search and it's been covered in these forums. Looks pretty easy.

linen · Apr 9, 2013

Can you t the pumps back together before the swg?

mas985 · Apr 9, 2013

Parallel pumps will only produce twice the flow rate if the composite head loss remains the same as the single pump which can only happen with completely separate (and identical) plumbing systems. Sharing any of the plumbing between pumps will increase head loss and reduce the flow rate of both pumps and the more plumbing that is shared, the less the composite flow rate. If all the plumbing is shared, the composite flow rate is usually less than 10% above the single pump flow rate. However, sharing just the tees at the pool shouldn't reduce the composite flow rate by much. Maybe 10% for a flow rate gain of 90%.

Because of this effect, I would avoid sharing plumbing as much as possible even if it means that one pump has a little less head loss than another.