Size of sump for 90 G ?

[Regal]

Hi guys, new to the forum.

I have just recently picked up a 90 G aquarium and I am turning it into a reef aquarium. I would like to do a sump for this, preferably a standard aquarium, here comes the trouble, the tank has no overflows so I will be drilling the tank myself and using bulkeads. The pump I am using is a dart pump and it is rated for 3500 gph I am dilluting the flow to roughly 2650 gph.

The real questions are, what size of bulkheads should I use for drainage from the tank to the sump, should I use two? Would a 29 gallon sump be sufficent enough for this? I am concerned that teh pump will drain the sump to quick before the bulkheads can fill it, I want the sump at a consistent level.

Thanks and happy holidays,

David

[Regal]

I was thinking I could maybe control the drainage with a shut off valve?

[Aquattro]

Ideally you want something bigger than 29g for a sump. Power outages may very well over flow the sump, depending on your drain config and sump water level. And 2600 GPH thru a 29 might be a bit much.
For my 90, my sump is 110g, but you could probably get away using a 40g.

[Regal]

Thanks for the quick response. I'll try to look for a tank during boxing day. Any suggestion on the size of the bulkheads from the tank to sump? One or two?

[Chin_Lee]

at 2600 gph, i would be most concern about water noise from the overflow and drains.
I would consider 1.5" min and possibly 2".
If I were in your shoes, I would have 2 x 1.5" holes using the herbie method for dead quiet drainage.
The good thing with the dart pump is you can restrict the output without any damage to the pump. So if the 1.5" drain cannot handle the flow (which I doubt) you can tone down the output further until it can handle it. 2600 gph is a little high for a return through the sump unless you are planning to use the flow from the return as your primary source of circulation.

[mark]

RC has a calculator for drain size, here (http://reefcentral.com/calc/drain.php).

Heard Skimmin's tank setup with Herbie's and is silent with a Dart and believe was flowing ~2000gpm. Check his threads but he has 2x1.5" primaries with 2x1" for the backup. He also has quite the nice sump layout.

[Regal]

The dart is my only form of circulation for the tank. There are no overflows on the tank, I am simply using the bulkheads for drainage to the sump. Would you only suggest one bulkhead or should I go with a second if I were to have 2" bulkheads? Thank you for the link Mark. :biggrin:

[mark]

If you do try the Herbie method (if not familiar try a search), you need two drains, one being the primary, the second is an emergency so doesn't need to be the same size as primary. Also need to consider how you're going to get water back in the tank, through a bulkhead or over the top.

[Chin_Lee]

Regal
consider adding overflows to your tank by having some pieces of glass cut at a local glass store. Then just silicone them into place after you've got the holes drilled. Cheap and probably won't cost you more than $40 in glass and labour.
Is your glass tempered at the bottom? Are you planning to drill the side or bottom (if its not tempered)? the rate your bulkheads will drain the water will depend where its located on the tank. This is because if you have it lower in the overflow, it will have higher water head pressure causing it to drain faster. If its higher in the overflow, it will drain slower due to lack of head water pressure.

[Regal]

The bottom of the tank is tempered so the bulkheads will be going on the back glass of the tank around mid-section, the water will come back out from piping above the tank.

[Regal]

I am getting the glass cut this weekend, would a single 2 " bulkhead be enough for drainage if the bulkhead is one the side of the glass, not from the bottom?

[untamed]

It is fine to have the holes in the backwall of the tank. You haven't mentioned it, but you need to build an overflow box inside the tank. I think you'll need an overflow box that has top edges that total nearly 2 feet for that kind of flow rate.

As for hole size bigger is better. 1.5" might work, but 2" is better. If you make the first hole 2", you could make the 2nd hole 1.5".

Make two holes. Make 2 holes. You have only this chance to do this right and the best advice we can provide is to make two holes while you have the chance. That or live with the noise and don't come back asking how you can make it quieter....because then we will say...you should have made two holes!!!

Both holes have to be in the same overflow box.

Finally...I should mention that you should drill 2 holes....