I thought pump selection would be easy.

garynappi

I am in the process of expanding and converting all of my outdoor electric needs to solar, but I hit a stumbling block... namely the specifications of water pumps for my small (~20 gallon) garden "water feature" with goldfish and a couple of other small fountains.

For the fish pond I want a submersible with the lowest current draw with the most water moved for a small shallow pond with nearly zero water rise for the filter and maybe a modest fountain head with less than a foot of rise.

I'd likely use a pair of external valves to control the rise of the fountain head to keep the majority of pressure for the filter.

To start off I bought a 400 liter / 105 gallon per hour pump that draws .5A but it's totally ineffective for the filter, the water flow is way too slow. I had thought that totally recirculating /  moving  5x the water volume of the pond would be more than sufficient, I was wrong.

I'm now waiting for an 800 liter / 210 gallon per hour pump that draws 1a to be delivered, but my hopes are dim. If this one turns out unusable I can use this one and the other elsewhere.

So, does anyone have a source for a low current, low water rise, higher volume pump than I already mentioned or perhaps a guideline for pump selection that would help me decide on the optimal GPH / current draw?

jonr

To specify a pump, you need to know flow rate and pressure (or head).   Looks like the figure you are missing is pressure/head for the filter.

Very large filters tend to need low pressure/head (ie, are efficient).