Sump - well that didn't work
 

I am really glad I tried to put the 20L in my tank before gluing in baffles. It is too long to get in the stand. I can't cut the stand. I do have the receipt and could exchange it for a 20H. I also have a 15g (4" shorter than 20H). This is what I'm thinking of doing. I do want a tiny refugium section because I like the chaeto to pull out nitrate. The plan with this one is to have the skimmer in the first section, then a bubble trap with the baffle higher on one side which will make the water flow into the fuge section first, then the return section.

Or I'm wondering if I could make the dividing baffle between the fuge and the return section out of egg crate. I just usually get algae on the walls of the fuge and wonder if it would hurt the pump. I did it sideways to keep the light out of the return section. I could do it the other direction if I can keep the light out of the return section.

The main idea of the baffles is twofold. 1, fish can get to the sump---not often, but they may. To keep them out of the pump intake, you need one bottom-to-water level barrier closely set with a second, higher one that has a half-inch gap at the bottom. This will keep fish, snails, and weed from getting into the last section, which contains your pump. Eggcrate will not work, because it lets all the above through. Any fish small enough to sump-dive will go through the egg-crate.

My sympathies. In my 50 corner, I had to install the sump in the stand before setting the tank on, because there was no other way to fit it. You CAN set a sump in an adjacent piece of furniture, like a garage-sale barrel-style end table.

Would it be better to go no fuge?

For a tank under 50 gallons, fuge benefit is not that huge, but having a sump is.

I would personally not worry about a fish getting in the sump if you have your overflow in the tank secured. I think your design will work but you need to put some kind of slotted piece on top of the divider to keep the macro algae out of the return area. If you use acrylic for the barrier between the fuge and the return section just cut slots in the top to act like a grate. You don't need a fuge but they are nice even if just for a place to cultivate pods.

I have a jigsaw, I was planning on cutting slots in that but they're hard to draw on sketchup.

I just used a dremel, not perfect but not bad either. The jigsaw blade is a little smallish, so you would need to make a few passes. Lots of ways to do this. Gotta love DIY.

sk8r - any reason why I shouldn't do under-over instead of over-under?

I'd use the 15 for the sump - the taller 20 is going to be more trouble reaching into, which means more stuff will likely end up there. usually.

Can you fit anther tank sideways, like a 5 gallon or something? segregate the fuge entirely.

What kind of stand do you have because I just had this same problem and could possibly have a fix that actually ended up being 100 times easier than I thought it was going to. Do you have a pic of the stand?

I built it. Its got a 2x4 frame with 3/4 inch plywood skin, with nice panelling that I already painted. The top is solid plywood with trim on the outside. I'm actually pretty proud of how it turned out with the help from the guys on the DIY forum.

For the grate - I was going to drill a hole with a 1/2 bit, then just make 2 cuts to put the grate in.

Anyone know if you only have 2 baffles, can you do under/over or does it need to be over/under from sump to fuge like in the plan attached?