View Full Version : Drains on 330-350-400g

12/01/2008, 09:00 AM
Will two 1" drains be enough for a 330g tank? That would've been enough for a 240 but I'm wondering if it's enough for 330 gallons if I choose to order the 96 x 30 x 30...

At what point do you need more? Assuming that my 900gph Ehiem 1262 return pump won't be enough for a 330g? What is the formula for how much tank to sump circulation you need?

Getting a new Dart return and converting my 1262 to a closed-loop would be an option but do I NEED to?

12/01/2008, 10:26 AM
FOWLR or reef? I'd say reefs NEED more flow than a FOWLR, although FOWLRs certainly benefit from high flow as well.

If you're going to have powerheads in your tank, then really you dont need a huge volume of water flowing through a sump, two 1" drains would be more than enough. My 210 has two 3/4" drains (the standard on the predrilled All Glass/Aqueon aquariums) and has quite a bit of flow. 1" holes flow about 60% more water through them than a 3/4" hole, so you should be just fine.

12/01/2008, 12:16 PM
If you are keeping your eheim & do not plan on going with more flow at a later date the 2 - 1 in drains would be fine.

I would think you should go with a larger pump, like a reeflo snapper or dart (like you mentioned) flowing 2000-3000 gph. Use one of the returns to go directly to your skimmer so around 500 gph should be put into your skimmer.

I have always been told on my FO tanks (old school, I use a wet/dry) to go with a turnover in the 4-6x's area.

12/01/2008, 01:47 PM
It'll be FOWLR....

Can two 1" returns handle 3600 gph(dart)???

If I really need more flow I can add some Tunze streams or something. I'm just thinking about how much water is going to the skimmer/sump to do the processing I need.

My skimmer will be an in-sump Octopus pro 300 so I won't be draining to it directly...

12/01/2008, 03:29 PM
No, two 1" returns wont be anywhere near 3600 per hour.

Pressurized and pumping flow rate through two pieces of 1" PVC could maybe hit around 3000 gph, but just simple gravity fed you'll be lucky to hit more than 1500, probably even less.

12/01/2008, 04:09 PM
So what then, two 1.5" drains?

12/01/2008, 04:58 PM
Kind of getting out of the realm of what I have experience in, but google search drain rates through PVC and you should be able to find an answer as to what size pipe you'll need to get 3000+ gph out of two drains. If it was me and you could get custom size holes, just go for two 2" holes and you know you'll be good to go, those should easily handle 3000 gph even at just gravity feed rates.

12/01/2008, 07:35 PM
like they stated, two 1 in drains will not be close. Two 1.5 or 2 in would be pleny for 3000 gph.

You might want to look at converting the skimmer to RC. That seems a little on the small side for a 300-400g tank so you might want to mod it so it performs better. I would think for a FOWLR you would want something at least 10 in in diameter??

12/01/2008, 08:04 PM
I am using 3 1.5" drains for my 600 using a Dart return pump. One is a spare so I am actually only using two 1.5" right now. They handle the flow from the Dart just fine. It is alot of flow thru the sump though. Make sure you have a decent sump.

12/01/2008, 08:11 PM
I pump 5000 gph and I have (2) 1 1/2" drains. So you could probably get away with 1 1/4"

12/01/2008, 08:44 PM
You might need 2 x 1.5inch drains. My 200 FO DT has a single 1.5 inch drain and I push 2000gph through it. This makes 10x turnover with the return. I've got another 40x in powerheads.