Biocube 29 gal - how to control filter chamber height?

[saltyfish24]

Hi,
I'm trying to understand the how water height is adjusted in the filter chambers of a BioCube. Before I brought it, I thought the water level would fill up all 3 chambers. Now that I have it running just water, I see that's not the case. I'd like to use the middle chamber as a refugium with a bit of rubble and chaeto and pods. I'll be lighting through the back glass.

How do I increase the height of this middle chamber to maximize the amount of water volume available for growing the refugium? Do I add a sponge to the bottom transition between chamber 2 and 3 to restrict the flow escaping chamber 2? Or add more water to the tank? Or add more water to the filter chamber?

When I'm just running water without any filter material, chamber 3 is running low. There are marks on the sight glass on chamber 3 to indicate the max and min water level. I'm a bit below the minimum water level when just pumping water around. Do I fix this by just adding more water to the tank or to chamber 3 directly? For future reference, if I replace the return pump, do I need to be very aware to replace with the same GPH pump? Am I right in thinking that the water flow design restricts this setup to a very narrow GPH pump?

Water level very low on both the refugium chamber and the return pump chamber:

 

[Brady4000]

How do I increase the height of this middle chamber to maximize the amount of water volume available for growing the refugium? Do I add a sponge to the bottom transition between chamber 2 and 3 to restrict the flow escaping chamber 2?

Yes you add more water to the tank, until the level is where you want it. The back of the tank works the same as a sump. The back of the tank will have less water when running and fill up as soon as you turn the tank off, so when you have it running start topping off your water to where you want it.

I do have a sponge in mine in-between chamber 2 and 3. Never removed it to see what happens. Chamber 3 should be much higher than 2 when the cube is running. All three will level out when you turn the pump off.

When I'm just running water without any filter material, chamber 3 is running low. There are marks on the sight glass on chamber 3 to indicate the max and min water level. I'm a bit below the minimum water level when just pumping water around. Do I fix this by just adding more water to the tank or to chamber 3 directly?

I run mine well above “max”. You’ll know where to stop, because your filter floss in chamber 2 will be submerged in water and you’ll have to dump some out to keep it above the water line. Just add water to the main tank (while it’s running) until it’s where you want it.

For future reference, if I replace the return pump, do I need to be very aware to replace with the same GPH pump? Am I right in thinking that the water flow design restricts this setup to a very narrow GPH pump?

I wouldn’t worry about finding too strong of a pump that will fit in that tiny space, but I would definitely not get a weaker one.

 

[Brady4000]

As for my setup. I have a 32, I don’t think the 29 should be much different.

Chamber 1
-Skimmer.
-Heater
(This is what I have)

Chamber 2:
-Filter
-Media bags

I have:
-InTank Media Basket: filter floss and Chemi-pure blue
-InTank Refug

Chamber 3:
Pump

I have:
-Pump and UV

I have my build in my build thread for ideas.

 

[Wilsonl2010]

Hi there! I’d like to piggyback off the original question. I just inherited what I believe to be a BioCube 29. It’s an older model I’m assuming because the back is not transparent. Here’s my problem; the water level in the third chamber with the return pump is barely able to keep above the minimum line, but the actual tank is so full, water is overflowing into the second chamber and so is all the flake food I put in! Please advise!