Sump Experts

[Zer0]

Alright this is a question for the experts on sumps. I need to get an overflow box to work with a sump, and the overflow box that i want to get is going to be returning water via an aqua-list return pump. The pump is rated at 300GPH. So knowing this, would something like a 20G high tank be able to handle 300GPH? and the skimmer and filter still work appropriately?

 

[CaptainAhab]

It's not the tank you need to worry about. A 300gph return is pretty small. A 1" drain (overflow or drilled) drains at approx 600 gph. Your overflow needs to only drain at approx 300gph or u have a sump flood (unless you restrict it somewhere).

Question, the 300 gph return.. You're sure that's 300 gph at the headheight you need right?

But to answer the direct question.. a 20G tank is fine for a sump.. I would venture a guess that alot of us have sumps in the 20 gallon range.

 

[Zer0]

Well then what would be an appropriate GPH for returning water through a 20G tank? Im not really sure as how to measure this by.. head height. Would i be better off going with a 600GPH+?


The overflow box that i wanted to get only had a 3/4" bulkhead.. so i would guess that a GPH of 300 would work considerably for it, but imnot sure. what do you think?

 

[CaptainAhab]

Forget the tank and think of it as a math problem. You have a hole in your tank flushing water at a certain GPH into a container. You have a pump in the container pumping water out. If the pump doesn't pump at almost the same rate at the water is flushing you have a container overflow. If the pump is too big and it pumps water faster than it is getting water then your tank will overflow. If they are roughly equal, all is right with the world. Water in = Water out = Water In .. etc

Headloss is how much power you pump loses because it has to pump water up hill to get it back in the tank. It may be able to pump 300gpm in a str8 line but when it has to pump it 4 ft up from the sump and over the rim of the tank, that takes a beating on the pump (not in a bad way) and requires more effort. More effort, slower pumping. slower pumping,less gallons moving....

Your pump should have a headloss paper w/ it. If not the manufacturer will have one. There are other things to take into account also, how many bends are in you pipe, couplings, etc etc etc

Look here.. Reef Central Online Community

Make sense?

 

[Zer0]

Makes alot of sense. Thanks for spinning the yarn for me.

 

[partypalooza5]

Oh so NOWW your going to get a sump XD

 

[Zer0]

But see, if im getting an overflow box kit, that has a pump specifically made for the overflow box, and it takes into consideration the flow rate as well, then shouldnt it work like its supposed to?

In other words, lets say i got an overflow box with a 1" bulkhead. Then getting something like a 650GPH or 700GPH pump with a max head height of 9.5ft, then wouldnt it work perfectly? its 750gph @ 1ft.

Well, im not sure if im getting a sump just yet because i want these calculations to be just perfect before i go out and buy something that either will overflow my sump,or not pump water to my tank fast enough. Plus i have some extra $ now because my mom wants to "invest" on my SW tank and shes going to pay half for the LR. xDD How lucky i must be..

 

[CaptainAhab]

You would think so but......

Do you have a link to the one you're looking at?

I'm always more comfortable buying the pieces I need. That way I can get exactly what I want and that works for me and not what someone else thinks I need. There are good pumps, bad pumps, fire hazard pumps, loud pumps, etc (all highly subjective of course).

Frankly I never heard of the brand you listed and Google turned up nada as well... Just saying.. It's not just your tank but a big expensive mess if it overflows to take a chance on it.

Anyway, as to your example.. it doesn't always work that way.. Each pump will have diff headloss numbers.

For example. I have a 1" drilled tank and a Mag 9.5 running that I have to restrict just a tad to make it all work out based on my head height (stand height, tank height). Now you may have a 75g instead of a 90 and prefer your stand to be lower. Put my 1" drain and pump on your tank and you may have a disaster. It's just not cookie cutter which makes me leery of packages unless it's the full monty.. tank, stand, sump, overflow, pump.

Anyway, don't wanna beat the dead fish too long.

 

[jessicasmarine]

A 1" pipe drains 600 gph and the pump pushes 750gph, unless you restrict the flow as Captain Ahab suggested then your DT will overflow because the overflow cant take out what the pump is putting in

 

[Zer0]

So in other words, if i get an overflow that has a 1" bulkhead and a flow rate of 600GPH, then to the best of my abilities, i would get a pump that pumps water out of the sump at 600GPH.. rriiiight?

 

[CaptainAhab]

again, you have to take headloss into consideration as well

 

[Zer0]

Well how the heck am i supposed to take headloss into consideration when the pumps dont mention anything about that. I looked at the link you gave me before for that calculator thing, but it only has a limited amount of pump brands.. so idk what to do here.

 

[CaptainAhab]

call/go to where you are looking to buy from and ask for it.

 

[CaptainAhab]

So in other words, if i get an overflow that has a 1" bulkhead and a flow rate of 600GPH, then to the best of my abilities, i would get a pump that pumps water out of the sump at 600GPH.. rriiiight?

 

[Zer0]

Alright well the message is clear. So now ill do what i can to get the correct equipment. Thanks for the help guys.

 

[gzeiger]

As long as the overflow rate is greater than the pump output, you're fine. Water won't enter the overflow box any faster than the pump puts it in the tank, since the tank's level will just drop until it's right at the top of the overflow box and won't drop any further.

 

[HN1]

Do you have valves inline with the return pump? I struggled BAD with the plumbing of our tank because of exactly what you are facing, only opposite. Our return pump moves a massive amount of water compared to the overflow so I had to dial down the pump output with a valve. Definitely listen to the Captain on this stuff and check out everything you can. If you can get a valve inline, you won't have to worry about exact calculations because it will allow you to tweak it. Here's our build link on the club site. Sadly, it got more plumbing critique and suggestions than the thread asking for help. Go figure... lol Hopefully there is something that may help you out in there.

50G build, upgrade from 20g. - Atlanta Reef Club Forums

 

[Zer0]

Thanks for the link HN1.

Anyways, let me put it this way. I have 4ft to the top of my tank, and im going to be getting a 20G high tank as a sump. Would an overflow box with a 3/4" bulkhead be ok with something like a 350-400gph return pump? what do you think.

 

[HN1]

The biggest lesson I learned is that you want the overflow wide open and a pump that can easily meet the volume. With a valve on the return, a bigger pump is better and you can control things more exactly. Our return pump has a 700GPH and a rise of probably 3'. Our return valve is at about 30%. The sump runs at about 40% volume. This allows us to keep the display (50G) level above the trim and for the sump (20 long) to hold any water during a power outage. Definitely test that part!

*disclaimer* I am honestly a total newb with plumbing and it took longer than I liked for things to "click". Listen to Ahab and others with more experience.

 

[Zer0]

Alright, i like the idea of a valve on the return so i can get a pump that is rated higher than the bulkheads flow rate. But how do you put a valve on the return line? and better yet, what does a valve for a return line look like?