Hmf filter

[Andy27012]

These seem like a cheaper alternative to the air driven hydro sponges that are popular. It seems like they would be really good for a fry tank. Anyone have any experience with them? Here is a link to a design I like. (https://m.youtube.com/watch?v=kMqZ3DKnpJ8)

[100fuegos]

I do. Mine is rather small compared to that, 1/4 maybe, corner type. It is in what it was a guppy and shrimp tank. I cleaned it for first time after maybe six months when I noticed like a 1/2 inch difference in water level. It works real nice plus it allows to hide the heater under it. I used a piece of 20 ppi poret foam.

I tried first with an elbow like in the video but a curved tube works way better. Besides that an air stone will greatly help with the water flow. I use a piece of 1" pvc reduced to 1/2" with the elbow. Take a look at swisstropiclas for ideas and a place to buy the foam.