My sump plans, will they work properly

[wickedpaul]

I am going to attempt to build a sump for my 55 gallon tank. I will either use a 15 gallon tank that I have or a 20 gallon long tank located inside my stand. I am planning to use a pair of powerheads to run the system rather then a syphon. Please tell me if you see any horrible faults with my plan.
To carry water to the sump, I plan to build a small box, with slots that sit 1 inch below the water line and a powerhead inside of it, running a hose to chamber 1 of the sump. 1 inch of water in the 55 gallon is 2.7 gallons of water.
Sump will have 4 chambers, chamber 1 is inlet, and bioballs, water will flow out the bottom of the chamber to chamber 2. Chamber 2, sand, microalgae, rock. Water will flow over the wall in to chamber 3, where there will be filter media. Water will flow under wall to chamber 4. Chamber 4 will house a return powerhead. The combined total water capacity of chamber 3 and 4 is 2.7 gallons. If I have a failure in one of the powerheads, neither tank can drain out more then 2.7 gallons, so neither tank can over flow. The 15 gallon tank will hold 12.15 gallons of water.
Protein skimmer, and heater will be in the sump. Is there any reason why this set up will not work?

 

[squidd]

Please tell me if you see any horrible faults with my plan...

I am planning to use a pair of powerheads to run the system rather then a syphon.
You just answered your own question...

 

[wickedpaul]

Originally Posted by Squidd
You just answered your own question...
Thats not very helpful. Why is it a bad plan? By using the powerheads I can completely control the waterflow speed. Could you be more specific?

 

[fishntx]

when runing two powerheads like that it is just a disaster waiting to happen. you will have to get both running the same amount gph. if you do manage this down the road the will start to weaken at different rates and the what you got is a big mess to clean up. best to go with the siphon overflow.

 

[wickedpaul]

Originally Posted by fishntx
when runing two powerheads like that it is just a disaster waiting to happen. you will have to get both running the same amount gph. if you do manage this down the road the will start to weaken at different rates and the what you got is a big mess to clean up. best to go with the siphon overflow.
Problem with that is that the tank is already in place. How can I install an overflow on a tank that is already running?

 

[turningtim]

HOB (hang on back) overflow. How much room do you have between the back of the tank and the wall?