reducing a powerhead's flow

[mellowvision]

I've been on a quest for a tiny low flow powerhead, and seem to have come up with only 2 options with everything I need, neither is perfect.

The AquaGlobe Micro Pump 175 is the smallest I've seen, and has an integrated basket with a super small sponge. It is, however, a very fast pump, even with it's flow restrictor closed. I also wonder if the sponge is large or dense enough to make a decent sponge filter, or keep shrimp fry from getting sucked in.

The Rio 50 Mini Powerhead is quiet and low flow, claiming 69gph, but is bulky and large, and the flow restrictor is long and it lacks any position adjustment, unless you wish to add another flow tip piece.

Since this is for a tiny tank, both of these create quite a bit of current. I'd like to reduce this, and diffuse the spray.

How much of a flow reduction can these powerheads take without breaking down?

Do you think the sponge on the AquaGlobe is enough of a filter for my planted 4 gallon shrimp tank?

 

[mellowvision]

also the suction cups on the rio fall out of the housing before letting go of the glass... such a PITA!

 

[jm1212]

how about an Azoo palm filter?

 

[mellowvision]

can't have an hob. I am trying to find a way to use what I have. the rio works but is bulky and looks like crap in the tank, the Aquaglobe looks pretty ok but is too fast flow and has a tiny sponge.

 

[msjinkzd]

I think that with how low of a bioload that shrimp have, and the fact that your tank will be planted, the sponge will be perfectly adequate. Go with the one that is more aesthetically pleasing to you.

 

[rwspear76]

is there a way you can increase the size of the outlet? Remember the larger the hole the slower it will flow, the smaller the hole the faster it will flow

 

[mellowvision]

there is no way to enlarge the hole enough to manipulate flow. I can slow the flow by adding a restrictor somewhere, either a cap with little holes on the outflow, or by stuffing the strainer basket with foam on the intake. I can figgure out how to slow it down, but don't know how much flow is required to keep it from burning out. going from 175 to 40gph is a big slow down.

 

[ibr3ak]

is there a way you can increase the size of the outlet? Remember the larger the hole the slower it will flow, the smaller the hole the faster it will flow

I was about to suggest something like that but for an intake, block the intake with something so the opening is smaller. ZooMed powerheads have a similar flow control on them (by either opening the intake or closing it).

 

[mellowvision]

it turned out that a black rubber grommet I had fit inside the filter intake snugly, allowing me to reduce the intake on the Aquaglobe to 3/8". then, I stuffed the strainer with foam, floss, windowscreen and more foam, and replaced the strainer. it now flows pretty slowly, I'm trying it out to see how it goes.

 

[ThePBM]

how small is the tank? my planted shrimp tank just has a sponge filter run with a tiny airpump, and the shrimp do great.