Plenum size for a FISH ONLY 90 gallon

Curious as to what you recommend for a pretty heavily stocked fish only 90 gallon tank as far as plenum size. I do have at my disposal a 20 (30"/12"/12&quot gallon "long" tank I could use as the sump in which to build my plenum. Would this be large enough? How high should I go?

 

On a 90 my guess would be that 20 long might work ok but doesn't give you much room for error or give you maximum return. I will ask an 'expert' I know and get back back to you.

I would stick with the 1.5" plenum and 4 inches of sand routine as outlined in the sand section.

 

i found a really good site about plenums maby this will help u out

its got what u need to make one the supplies and instructions

http://www.pgjr.alpine.k12.ut.us/aqua/plenum.html