I hope this makes sense.

From what I remember, there are bubbler filters. Basically the bubbles flow up through the sponge filter, through a pipe, and the bubbles actually FORCE water to move upwards with it, causing new water to be sucked in through the sponge holes to replace the preexisting water... Creating a cycle.
Like these:



Can I apply that theory to a scrubber?
Specifically for my fry tank. My fry tank is a 48 gallon hexagonal tank. It's one of the wider ones, not the tall ones.


In the picture, you see an above view, and a horrible side view drawing.
There's 2 panels of plexy glass. The first panel is only like 4", to hold the sponge up against the 2nd panel, which sits an inch or two off the bottom and top of tank. So water can flow under, and over it.

Bubbler and an algae screen behind it.
Light shines through the back.
The water will create a current that gently flows over the top of the 2nd plexy glass screen.

The sponge is just to help catch particles and keep fry out of that area. Open cellular sponge that I can just occasionally ring out.

Again if this looks weird, it's a poor hexagonal drawing on gimp lol.

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The only CONs I can see to this set up:
**With the screen being in a small enough space (small space to help create current), will that provide too much water/air/light mixture to the back of the tank and the 2nd large plexiglass panel? Causing it to grow algae too?

The pros are:
**I can get color'd plexiglass to block out some of the red lighting Or instead of plexiglass I could use coroplast. A black coroplast sheet will block out most light. Especially purple from the 660s and 455nm LED mixture.
**With the prefilter sponge no fry will be sucked in (this is a growing tank for my dovii and jaguar cichlid fry).
**No sump will be needed.
**The sponge can also serve as a mechanical filter for debris.
**The fry can't feed on the algae - if they would?



I'd put the algae scrubber in the middle of the tank... The biggest problem I THINK I would have is fry eating the algae.
Fish do that right? They pick away at it all day I hear.