Overflow Diameter

[rdhughes_1]

Hi all,

My wife and I are building a 150g (624X24) reef tank for our home. On my past tanks, I have only used HOB skimmers, so the concept of a sump is foreign to me.
Our LFS is willing to drill whatever drain/return holes we desire, but I am unsure of how large we should request. (One overflow will be used, in the center of the back panel.) The plan is for one Dolphin 3000 to return the water through 2-1 inch sea swirls in the tank (I don't want additional powerheads in the tank) for a total circulation of approximately 2100 gph.
It seems as if the prudent idea is to drill the returns at 1" each, but what about the drain? I would rather err on the side of conservatism, in an effort to prevent an overflowing tank. Will 1.5" provide this type of flow, or should I use a 2" drain?
The reason for the confusion is with the 2" drain, a 24" overflow box is required. Obviously, this takes up considerable room inside the tank.
Any ideas?

Thanks,
Robert

Thanks

 

[nickthapainter]

For a reef tank you may want to shoot for a little more flow in your tank (depends on the types of corals you wish to keep of course).

20 times the tanks volume per hour is an acceptable amount (more should be sought if keeping an SPS tank)

For a 150 gallon tank that would be minimum 3000gph.

The 1 inch Seaswirls will run you $180 a piece (total $360) and the Dolphin $285 -- from Darin @ Captivereefs (awesome bloke). The total flow is 2100 GPH for $645.

For $245 more you could order a Tunze Stream kit TS 12 -- comes with 2 pumps (max flow on each is 3175 gal per hour), digital flow controller, moonlight and all the bells/whistles -- plus a return pump from your sump (Mag9.5).

Overall flow with a 1 inch overflow (600gph) would max out at almost 4000gph. The Tunze is bloody awesome -- tidal, surge, feeding, nocturnal, chance flows are programable. The moonlight even replicates the 28 day lunar cycle. The hardware comes with a 2 year warranty and the Tunze US rep offers excellent customer support (Roger Vitko @ Reefcentral.com).

I'm in a similar situation, as I don't want a multitude of powerheads in the display. One option is running closed-loops to get a larger volume of flow. My condo association banned me from doing this (worried about the neighbours underneath); so I've had to opt for the Tunze option. A little added benefit on my end is for power consumption -- each pump consumes only 45 watts of electric!

Anyways, it's worth thinking about. More flow, more natural, but more money -- (fiancee is ready to call it off when she found my expense log for the new tank!)

 

[nickthapainter]

almost forgot....

Welcome to Aquarium Advice (my favourite place on the Web)

 

[seaham358]

I have 2 bulkhead returns on my 125 reef..... drilled 1 3/4 hole for a 1" bulkhead. Have them plumbed into my reef devil sump w/ skimmer.....
Your LFS should know wha tis best if there any good? If ther not you may want to shop around. You can but predrilled reef ready tanks also. Check all glass web site for a list of tanks and gph rateing...