Questions on building a sump

[Fireworks]

I am considering building a sump for my 150gal reef setup, and after reading all the helpful posts from everyone, I have two questions to ask.
First, how is sump size determined, and second, what is the ideal flowrate through the sump.

My tank is as I stated above 150gal and measures 48"by24"by 30"high
I do not have an overflow and am trying to gather the nerve to drill a bulkhead in. Thank you in advance.

[taosku]

this post comes handy

i also want to build one for my 75 gal FO .

what size should it be ?

will post later when at home the space i have under my tank .

[loganj]

What type of sump did you have in mind? And how much flow do you have in the tank now without a sump? There are so many combinations. If your sump isn't going to incorporate a refugium of any type, then you don't need a huge amount of flow through it. The higher the flow through the sump, the greater likelihood you will have problems with bubbles being returned to the main tank. As for sump size, bigger is better. The larger the sump, the more room you have for equipment. Your sump has to be large enough to handle the drainback from the main tank. In your tank, there is about 4.9 gallons of water per inch. If your water level in the main tank drops 2" when you shut off the sump pump, you will have to have at least 10 gallons of capacity in the sump in addition to the water that is normally in there when the tank is running. If you had a 29 gal tank for a sump...and you wanted to run it with about 12" of water in it...that's about 18.6 gal which doesn't leave you a enough room to hold the drainback from the main tank in the event of a pump failure. Take into account any equipment that will be sitting in your sump as well...skimmer...submersible pump. These take up space and will reduce the available water capacity. The formula to figure this out is length x width divided by 231...that will tell you how many gallons of water is in each inch of tank depth. Length x width x height / 231 will give you the approximate capacity of a tank in gallons. Once you get this calculated...and decide what you want the sump to do, we can talk flow rates.

[Fireworks]

Thanks Loganj, I was not planning on having a refugium but may install provisions for one later (valves etc). Right now I have around 1800gph flow, should I aim for that amount through the sump or would more be better? I had thought of using a 40gal breeder tank for the sump and maintaining a 20gal operating level. With the 10gal drainback, that leaves 10gal space as a comfort level. How does that sound?

[melosu58]

Moved to Hardware and equipment discussion

[loganj]

1800 GPH through the sump is fine if you construct your baffles in a way that will control the bubbles. There will be a lot of microbubbles with that much water dumping into the drain end of the sump. What do you want in the sump as far as equipment? Will you be using an in-sump skimmer? If you wanted to do a mud sump, that flow would be about right. With a mud/caulerpa sump, you have a fuge incorporated into your sump. Refugiums typically are separate tanks with relatively low flow...which is fine if that's what you want. Do a Google on Ecosystem mud filters and read up on the theory behind that type of sump and see if it intrigues you at all. I can tell you from experience that it works. If you have the money to spend, it's nice to order one of their sumps and just plug it all in and start it up. If you're like me and paying all the monthly bills is a juggling act, then know that you can build your own. How much room do you have under the stand? If I remember correctly (which is always suspect), a 40 breeder is 36x18x13. If you go with a 50 tall, you have the same dimensions except that it's 17" tall instead of 13". Now you can run 30 gal instead of 20 and still have 10 gal of "extra" room. Ok...now IMO, you don't need that. Your main tank will always drain down the same amount...every time. So, you get the tank running with some water in the sump. Shut it all off and let it drain down as much as it's going to. Fill the sump on up till it's about 1" from the top. Turn the pumps back on and mark the new operating level of the sump. This is where you can safely fill it to. In a tank with a 36"x18" footprint, you have about 2.8 gal per inch. By closing the margin, you gained about 7gal of water in the system. I don't mean to make this sound more complicated that it really is, but a poorly designed sump is a pain...a well designed one makes tank maintenance and upkeep much easier. Tell me what you want to run in the sump and I'll try to be more specific. If you're just going to use the sump to house equipment, then I'd probably be inclined to drop the flow to about 1000gph and run a closed loop pump in the 1200-1500gph range for a total flow of about 2200-2500gph or 20x tank size. JMHO.

[Fireworks]

Thanks again for your help.As of right now I just want the sump to hold all my equipment and replace the cannister filter I currently have now. I have an in-sump Euroreef skimmer that is mounted in an elaborate setup above the main and piped in. I should add that my tank is mounted in a wall in my basement with a large open space behind it and the steel stand I welded up will not allow an 18" wide tank under it (serious overkill on the stand) however next to the tank under the sink I installed, I can fit a 40 breeder or (and I like your idea better) a 50 tall nicely. The mud filter system does intrigue me and I will read up on it but for now I would like to simply get all the gear off the back wall and into a sump. What sort of provisions could I install if I wanted to go the mud filter route later on?

[loganj]

I'll try to draw up a diagram and post it for you. PM me if I forget you...workin about 15 hrs a day, but I'm off for 4 days starting Sunday.

[clr_newbie]

I designed a 40 gallon sump similar to the thread in the DYI forum http://www.aquariumadvice.com/viewtopic.php?t=53046. I had to modify the spacing of the baffles slightly to accommodate my equipment but it has been working great for over a year. My nitrate levels would never be zero pre-sump, post-sump they have never tested above zero. I do have a fuge like the DIY design with lots of cheato. Just my 2 cents...

[Fireworks]

Thanks for your input. The sump you describe is pretty well what i'm after. The only difference is I will be using a 15gal square tank that I currently use for my skimmer as the refugium. This tank is aready drilled for an 1 1/2" bulkhead and should fit really slick next to the sump.I would however like to add a compartment that could house filter floss or foam to provide some more mechanical filtration. Any thoughts on this idea?