Cinderblock and 2 x 4 Rack Question

[umfalcon]

Hey everyone,

I'm building a fish rack using Cory's cinder block and 2x4 method. I know that I can fight eight 20 gallon talls, or four 55 gallon aquariums on the rack. Does anyone know how many ten gallons it could hold?

[umfalcon]

Oh, follow up question, how many 20 gallon longs would the cinder block rack hold?

[Ken Dyer]

My suggestion is to plan the rack around the tanks. The "beauty" of the cinderblock and 2x lumber rack is that it is modular and can be sized to what you want it to be. My first rack I tried to span 6' between cinderblocks with 2x4's and I wouldn't ever do that again. 6' was too much and led to a sag, 5' was marginally OK but still sagged, 4' seemed to be the sweet spot to span with 2x4's. The last two I have built I have used 2x8's and I like them a lot more personally as they are more rigid with zero sag/deflection.

When planning expect the tanks to be bigger than what they list as the rim extends and also plan so that the tanks don't butt up against each other as it can make lights/cords a pain. Also I definitely recommend ample space between the levels so that you have room to add hardscape, net out fish, etc. So a good 8-12" between the top of the tallest tank and the bottom of the shelf above it.

If you have any specific questions just holler and I am happy to measure what I have done or tell you what else I did wrong and hated 😉 Or how many days/hours it takes to drain all your tanks, move them all, re-set them up, move them all again, and set them all back up a 3rd time to determine that 6' & 5' gaps are "too saggy" to let me sleep at night.