Sump questions!!

[Francois]

Hi, so, I will start a FO with fake corals and no LR. My tank is 55 gallons, I want a 20 gallon sump, but, it does not fit under my stand, so, I will buy 2x 10 gallon tanks, and drill a hole and connect them together.

Now, here are my questions, considering that my total volume will be 75 gallons, what GPH do I need?

Then, what type of design should I go for. Should I devote one of the 10 gallon tank completely to filtration, and in the other one, have skimmer and return pump? Or, is there a better design?

What do you guys think of this overflow box Reef Aquarium Filtration: Eshopps Overflow Boxes

Which model should I buy, if I go for the 300, than my gph question is answered

How big should the hole between the two parts of the sump be?

Thanks

[Francois]

Also, Do I need to exactly match the GPH of overflow with pump?

[ToddTT]

Your overflow needs to exceed the output of your sump's pump.

As far as total GPH for your system:

75 x 10 = 750 GPH

75 x 15 = 1125 GPH

I'd aim for somewhere in that range. You'll get this by adding your sump pump + powerhead(s). You don't want all that GPH going through your sump.

A Mag 2 or 3 in your sump, plus a single powerhead in your tank would probably be a good combination.

Live rock will help your filtration and water quality greatly, you should consider it.

You want to spend a few hours on this site:

Melevsreef.com | Acrylic Sumps & Refugiums

[Francois]

Fact is, I already read that website.

Thank you for the gph advice.