need advise/ideas cant decide on sump design

[somefinnfishy]

OK I bought a new drilled 55 AGA with the factory overflow kit.
Built a twin 55 stand the over flow tank will sit on top.
Now is where I need advise sugestions.
Do I add two 25talls? One a sump the gets feed buy the output on the 55 over it then over flows to the other 25 as the sump.Option I kinda like is to add a glass plate to the bottom 55(divide it) leaving a 1.5 foot sump space the glass divider will have a black acrylic overflow strainer box siliconed on to each side of the divider and a u tube conecting them.Now how high should I divide them so it something go wrong with the u tube water will flow to the sump anyway?
What kinda height difrence between the over flow boxes in the sump.My filter will consist of a BIG sponge thats it.You kinda see where I going with this any sugestions will help.

 

[somefinnfishy]

This will be a high light planted setup CO2 injected hence the sponge instead of a wetdry.

 

[BK]

i am confused about your description. you have 2 55 gallon tanks and 2 25 gallon tanks?

 

[somefinnfishy]

My choice is for the bottom is between 2-25s or one 55 the top tank will be the 55 overflow.
If I use two 25s one will be a sump.I'm thinking of divideing a 55 like a 1/3 2/3 split and need some advice on how to best make this a reliable sump.
Basicaly do I use 2-25s or a divided 55.
Also fishing for ideas on any of this.

 

[BK]

I am no expert but i would use a 55-gallon due to the ease of not having to mess with u tubes. If you were planning on using the rest of the bottom 55 as an extra tank I would set one up like this

the water would flow from the top tank to the container suspended in the bottom tank. In this container a sponge would sit above a grate so gravity would draw water trough into the main chamber on the bottom 55 filtering out waste. It would have an overflow notch at the top so if the sponge clogged the water would flow into the tank. Then the water would go thought the main chamber on the bottom tank and the extra waste gained in the bottom tank would be filtered before it hit the chamber with the pump and heater by a sponge sandwiched between two pieces of "egg crate" after this it would pass the heater and pump and be transported to the upper tank. This sandwich could be made an inch or two below the top of the water to allow water to flow over it if this sponge clogged also. This setup would give you two sponges instead of one incase the bio on one got wiped out and would provide filtration before and after each "tank" section with fish. If you made the sections on both sides the same size and covered them up they would match and not be as obtrusive

 

[somefinnfishy]

Thats a better idea! i could make little doors to cover the sides
The plan was to grow out tank busters arrowannas,piranha,ect in the soft planted tanks water.Also the planted tank will enjoy the constant supply of nitrates supplyed buy a school of messy eaters.
I have the glass to insert on both sides.Have both tanks.
BTW the pump I have is a luguna 3000 1292gph attached to their biomax click conect pond filter.Flow will not be an issue

 

[somefinnfishy]

The top tank is drilled twice on the same side of the bottom so in pump pushes it up threw the corner overflow area then one of those fancy flexi tubes pops out near the surface.
Some salt nut will be so mad at me for keeping FW in there.