Help! Fish keep swimming into the sump.

So I started my cube aquarium about a month ago.
At the back it has a overflow to the sump. My problem is the My fish keep swimming into the overflow and dieing in the channel behind it leading to the sump. Ive tried blocking entry to it by means of sponge but this Ive just come back from two weeks leave and found my tank ruined by all the fish that somehow managed to get past the sponge and die there again, Any suggestions? How do reefers keep their fish from getting washed over?

I was thinking that perhaps a toothed grid like a comb would work but have not seen anything like it.
Any ideas?

 

Some kind of egg crate may be?

 

Can you post a picture so we can see the overflow?

 

Ill post pics this evening thanks.

 

Mmm...

Another solution is maybe something like a gecko mat that is used for the boot of cars. It is made from a rubber type compound and has 4 to 5mm square holes. This should be able to keep your fish out. Will post how it looks in my guppy breedinh thread a little later.

 

Was thinking of something like a strip of acrylic with slots cut in and mount it at the lip of the back wall so the fish can't jump over. -|_|-|_|-|_|-
Does anyone know where I can buy something like that as My cutting skills leave a lot to be desired.

 

If you go to a gardening place they sell a nice fine plastic mesch that you could cut to size and silicone/wedge in place. The only problem is that I think they only sell it by the meter...

 

Can try plastic world in JHB,a bit far but they do allot of plastics.Also while you are there you could make a stop at PetMasters,it's worth the visit while you are in the neighborhood.

 

Here is what the gecko mat looks like in packaging:


There are two sizes available here in one of the Mica stores: a 100cm x 150cm, and 100cm x 75cm. Think the smaller mat is about R70 and the bigger one about R100. Works very simple. Just need a pair of scissors to cut and silicone as Skye01 had mentioned should keep in in place. Wish I had a up close picture, but the holes are about 5mm x 5mm in size.

 

Thanks Everyone for all your input and for the effort! I think I'm going to head to builders after work to get some.

 

there is one thing i notice you never mentioned is the flow rate. almost all my tanks have sumps and i do keep the flow to a trickle if possible.maybe the fish are not swimming in but are being pushed into it.i use an egg crate type barrier which is quite narrow.i have them glued to the glass with a glue gun so it stays in place.the size of the fish also matters.mine are quite large so they cant swim thru.i also place batting that is slightly higher than the water level.the gekko mat should do the trick with smaller fish

hope it helps

 

Water flow is about 500l per hour but spread out over 50cm so its very low. I tried the netting but the brace along the edges was making it hard to stick down so I found an old 50cm ruler and cut slots into it and stuck that to the edge.
I will see if that cures the problem.

 

I have seen at Jungle Aquatics a clear Acrylic strip with cut outs in it - almost like a comb as you were saying - made especially to stop fish swimming over the edge. It is like a 1M strip.

 

Thats what I'm looking for! Just a pity they are in Jhb.

 

Why not just make your own like that from some perspex. As far as I know perspex should also be perfectly safe in the aquarium.

 

I did use a 50cm ruler, But As I said my cutting skills leave alot to be desired. I thought of it initially but I cant really find a perspex supplier in pta,