View Full Version : What size pump??

05-17-2009, 03:58 PM
I've been working with PVC hydroponics, and though I'm pleased with my results, I've also invested a bit more than originally planned.

I'm looking to build a simpler system. Basically, I'll be using 3 4x3 bins. I'll be running a 3/4 inch pvc that will pull from a separate bin with my nutrient, and split into 3 other 1/2 inch pvc to feed. They will all have 3/4 drain hoses to go back into the reservoir.

My question is, what is the minimum gph pump I will need to distribute water to fill and drain all 3 at once?

05-22-2009, 07:53 AM
GPM means gallons per minute and is a rate.

Gallons of reservoir/pipe size does not affect pump sizing unless you have a rate at which you apply nutrient.

05-28-2009, 04:33 PM
better questions to ask are:
1. are you flooding and draining the bins or are you just applying nutrient water at the top and letting it percolate down and back out the drain?

2. how high are you pumping the water? (usually from the bottom of the reservoir to the top of the container or flood level). Pumps have different flow rates for different elevations. example: a pump may pump at the rate of 20 gpm to 0 feet high but only 1 gpm to 5 feet high.

If flood and draining it may be better to pump the water up through the drain and when the pump shuts off, the water drains back down to the reservoir through the pump. I don't know if that is possible with all pumps, but I can do that with the ones I have. Otherwise, you have to size the pump to compensate for how fast it drains. (if you want to fill the container at 2gpm, the container drains at 4 gpm, you would need to fill the container at 6 gpm to achieve the 2 gpm)