How many overflows required

[fatjusto]

Hello everyone,

Im currently in the process of setting up a new tank 6' 2' 2'. I have two big pumps which I thought I could use(each one about 2900GPH) to run the system. How should I set it up, I havent drilled any holes in the tank yet and am wondering how many overflows I will need for these pumps? I want to try and maximise space in the tank but also dont want the thing overfilling?
Any help on this would be great.

Also, any advise on how I should plumb the system would be great

 

[matts125]

Welcome to reef frontiers!!!
you should look into a coast to coast overflow, you can mount them on the outside and they wont take up any room at all...

Matt

 

[Meche]

As far as overflows are concerned, it is not about the number but the length of the edge that water is allowed to flow over. There is a calculator for this floating around here some where. I'll try to find it.

I think most people here would say that a 2900gph would be overkill for a sump, but if you already have the pump, I don't think it will hurt anything by using it(might force you to have a larger than necessary overflow though).

What do you want to keep? Some corals like tons of flow so you might think about using a 3rd (smaller) pump for your sump and the other two for extra flow. Some people have 100gallons of flow per 1 tank gallon!

Lastly, welcome to RF, hope you enjoy it here

 

[Slickdonkey]

Wow, 2900 gph is a lot. Remember, generally you want the flow through your sump to match that of your skimmer. Maybe this pump would work better for a closed loop?

I went through this very dilemma myself.

 

[Krish]

Welcome to RF again! I just replied to your similar thread in the equipment forum so here's what I posted there...

Originally posted by Krish75
Welcome to RF!!! Nice tank dimensions!!! What do you plan to keep in it? As for overflows, I'd go with 2 simply due to the fact that the tank is 6ft long. Are you planning on using one of those pumps as a sump return? If you haven't decided yet, think about how much flow you'd want through your sump first. 2900 gph is a lot of flow going through a sump IMO...Atleast for me. I like to give my skimmer a chance at incoming water and not let it just zip pass it. Some people differ though and like high flow sumps for a number of different reasons. So, let us know how you plan to use the pumps. If it were me (and just my personal opinion here) I'd use those 2 big pumps to run 2 nice sized closed loops and use a smaller pump to be your sump return pump (maybe a 1200-1600 gph pump at the most) which will mean your overflows will only have to support 600-800 gph per similar to that of an All-glass standard 6ft tank with mega flow overflows. Just a thought...Good luck on the project

 

[fatjusto]

Thanks for the replies everyone....

I havent really got any rock solid plans in mind just yet, I was kind of hoping to just use these two pumps for the whole system if possible. This is my first crack at this size tank and really want to do it properly. Thats why Im here to get as much advise possible.

I really like the idea of a closed loop setup what do you guys think would be the best way to do this on my sized tank(ie diagrams maybe of design). I also want to keep everything underneath the tank(pumps).

I really want to keep SPS corals and so high flow will be best.

 

[Krish]

I really like the idea of a closed loop setup what do you guys think would be the best way to do this on my sized tank(ie diagrams maybe of design). I also want to keep everything underneath the tank(pumps).

Well drilling the tank IMO is always the best way and neatest. You can hide a lot of plumbing by doing this. If drilling isn't an option, you can still do closed loops over the top of the tank. Here are a few photos of how I did my closed loop on my "cube". The tank is 24L x 18W x 20H and I have 4 outputs coming from the closed loop (the 2 top outputs are "Y"d the 2 bottoms are singles) and they are supplied by 2 pumps (1 pump per side). Then I have my sump return I use for surface aggitation. So with my setup, my 38gal is just shy of 4,000 gph which is about 104 turnover rate (minus whatever headloss ) and my corals love it and I don't mind the look at all

 

[fatjusto]

Ok guys I have been thinking/reading quite a bit lately and going through the workshop threads and have realised I have a few issues(always the way) which I didnt really think about. Firstly, my tank is glass so have to limit the number of holes. The plumbing workshop has a design which I think might work nicely for my tank....
http://www.reeffrontiers.com/photos_members/data/500/snowtopplumb.jpg

1.I was thinking of running these 2 loops off my 2 pumps(ie one pump per loop) and just having them on a timer say 2min on 2 min off alternating. Is this bad for the pump to do this????? remember I already have these pumps

2.I am also not going to have a sand bed so should I extend the lower arms right to the bottom to blow off detritis from the bottom.

3.I was thinking of having 2 standpipes in the overflow, i have noticed alot of people run the sump return up through the overflow box. Will this be too many holes(3) and what size hole/pipe should I use for the return.

Any advice would be very appreciated

 

[fatjusto]

ok I have actually just got in contact with a guy who services pumps and he says that this wouldnt be a very good idea as it would greatly reduce the lifespan of the pump. Hmm back to drawing board

 

[NaH2O]

Welcome to Reef Frontiers!!!

I'm not sure the answer to your pump question (whether or not the on and off would be bad). Hopefully, someone with better equipment knowledge can help with that (EDIT: nevermind....I just saw your comment ). I have my closed loop split between left and right sides of the tank. The pump goes up into a motorized ball valve that switches from side to side based on the setting on the timer (~7minutes).

As for the return - I have mine coming over the top of the tank. It allowed for smaller overflow boxes, and I was able to attach a sea swirl to it.

Here's an image of my tank from the back:

and from the inside:

My return now comes from the right side of the tank, and flows through a sea swirl for added random movement.

Your return pipe size will be dictated by the pump you choose to use as a return.

Hope this helps a bit!