Large Tank Set-Ups

[turningtim]

You best off by seeing what will fit under the stand. If you can use a single tank and use baffles or 2 tanks piped together. IMHO you're right your fuge should be at least 20% (when you can) and 30 is better. Also as far as sump size, consider the skimmer you will use and what size it is (footprint) b/c it will displace water in the sump.
Off the top of my head you could use 2 29's. The fuge would be a tad short but you would have about 50 gals of water volume and they would fit under the stand.
In design you want the tops of both tanks level. Water will go to the lowest point. If they're level then all the extra space is used for backwash.
Like Ameno said with anti siphon holes in a OTT set-up will reduce the backwash but with a RR tank the returns are submerged so they will siphon until they suck air. You will need more backwash I believe with a RR tank.
Tim

 

[stdreb27]

Originally Posted by ameno

that's what I do, and if all is set up right that's only going to be maybe 5 to 8 gal. of water and drop the Dt level about 1/2"
I think we are misscommunicating. I'm simply saying that if you're going to use a 20 gallon sump. You are going to have problems with evaporation. Because within a day or two your water level in your sump is going to drop below the intake of the pump.
HOB overflows get a bad name, but that is just the cpr style that use the air pump to suck out that air bubble, a well designed U-tube style overflow won't give you any problems.

 

[ameno]

I agree with the HOB for a tank that size I would really consider having it drilled, also depending on the lights i would guess MH lighting would evarorate anywere from 2 to 4 gal per day. It would be well worth setting up an auto top-off system otherwise your going to have to add water on a daily bases even with a bigger sump in order to keep you SG more stable.

 

[dennis210]

DRILLED
40 g long or a 55g (the largest u can fit)
Coral life super skimmer
(if you can afford better go better!)

 

[tinmanny]

Drilling is not that hard just need to go slow. People on the large reef section can help you out a lot on that subject.
You could also put the 20gal up on blocks to make it even with the top of the 40 so they will share the load of a shut down and no flool. I am going to the same methood with a 30 40 and an other tank of about 50 or 75
Manny

 

[stdreb27]

Originally Posted by tinmanny
You could also put the 20gal up on blocks to make it even with the top of the 40 so they will share the load of a shut down and no flool. I am going to the same methood with a 30 40 and an other tank of about 50 or 75
Manny

That would probably be the best idea. If you level both those tanks off they will overflow into both.

 

[stdreb27]

Originally Posted by Dennis210
DRILLED
40 g long or a 55g (the largest u can fit)
Coral life super skimmer
(if you can afford better go better!)
Don't et a coralife skimmer, they are sub-par

 

[rinker]

Agree with the Auto top off system!!! I just put one on my 90 and it is worth every penny.

 

[grumpygils]

If you can do it, the best thing I ever did was connect my RO/DI unit directly to my auto top off. RO is in the garage and I ran a frig line under the house and up 12 inches into the wall behind my tank. No filling of the top off resevoir or anything. At the unit in the garage, I have a t-valve on the ro that also lets me fill tubs for water changes.
Mc