Outflow rate to sump

[British malcolm]

I'm looking into setting up a 600g tank. I've done some research on the return pump and reading up in best to have 10x volume return so was looking at possibly getting 2 echotec L1's they circulate approx 3100g each. What I can't get my head around is how do I work out what the inflow would be into the sump. I'm not good at physics and all that but if 6200g aren't going into the sump but it's coming out I'm going to come unstuck. Can somebody help me out please. Also am I best to have 2 return pumps or 1 big one, I was thinking of the noise and vibtation. ? And is echotec a good choice.

 

[willthethrill]

Read up on the bean animal overflow! Your drains will have to be a bigger size too. Not your standard 1 inch drains. Also, those pumps say 3100g but when you take into account head loss and elbows in the line and everything, it's not gona add up to 6200g at all. Look at the head loss chart for those pumps. Measure the height, and see more or less how much of a return rate you'll get. You don't need to know exact, just as close as you can estimate, and then make your drains handle a tad bit more than that and then you can slap in a ball valve or gate valve and match it up to how much your returns are putting out.

 

[British malcolm]

Thanks. I was looking at using a herbie overflow so I could put the tank flush to the wall so I could have a bigger tank. What's your thoughts? How do I work out what the outflow rate I'm concerned that either I won't get enough water to the sump or will get to much, or am I just being over cautious as if I go bigger with the drains I can then adjust with a gate valve. Is bigger better in this instance?

 

[willthethrill]

Bean animal is essentially the same principle as the herbie except the bean animal has a standby drain that takes in some water as well. Plus there are 2 emergency fail safes with that design. It's worth you thinking about, especially since you're saying its gona be a 600g tank. That's a lot of water on the floor if a snail or something blocks your drain, or both drains [emoji15]. And yes a drain that handles more flow than the return should be implemented. Especially for a herbie because you need to set that siphon. For example, Let's say your return pump or return pumps send out 2000 gph. You should make your drain bigger, probably 1 1/2" if it's only one drain. So now let's say you take it for a test run and your drains, as designed, drain water from your display faster than your pumps can pump out. Let's say 2500gph. You just go over to the ball valve or gate valve on your drain and slowly close it and wait until your overflow box water level evens out and you find your sweet spot. Bam done.

 

[British malcolm]

I've just done some quick reading on the bean and I think you give sound advice. Having the 3rd drain is probably a good move with such a big tank. I see no reason why I couldn't have the piping inside the tank behind a weir. I think with such a big tank I would consider have a weir in the centre with a coast to coast overflow. What do you think? A few questions on the bean though. The bits I've read it says to have the main drain about 1" below the overflow outlet but no more or less. Is there a reason for this, also why are the strainers facing down on the secondary and emergency drain. Sorry for all the questions but in a 600g tank it's recommended that I circulate 10% if I increase the drains to say 3" then I'm going to get 4000gph (based on 1 1/2" is 2000gph) would this be sufficient if I have powerheads etc in the main tank. Then also reading up its says that if my tank is more than 300g or 8ft+ then I should have 2 return pumps. What's your advice on this. ?

 

[willthethrill]

Check out bean animals website and every single question you have will be answered. Beananimal is the username of the guy on these forums that created the "bean animal" design years ago. He literally describes step by step what to do and why it's done that way.

 

[willthethrill]

Just google search "bean animal overflow". His page is called Bean Animal Bar and Grill lol

 

[mcarroll]

Certainly read up everything that's been suggested...but before you head off for the extra engineering and expense you're being directed to...

Unless you are doing something exotic in your sump, 2x to 4x would be a better target range for flow, and fits with "standard" drain plumbing. It's also plenty to supply skimmers and all the usual sump equipment.

5x if you want to be really conservative and assume your plumbing is going to close up over time due to buildup...more than that is generally a waste and can even cause problems for standard drains. (Noise and bubbles to say the least.)

That's only 1200 GPH to 2400 GPH.

Higher ratings are generally outmoded - leftover from before there were good flow pumps on the market like the Tunze Streams.

You also need to know the pumping height.

For example:

Assuming your tank is 6' high and you want 4x flow (40 gallons per minute = 2400 GPH), a Dolphin Amp Master 4750 would do nicely, delivering a little over 3000 GPH:
http://www.dolphinpumps.com/#!diamond-amp-master-pumps/c20nz

That's a really nice pump that you can get a lifetime warranty on (depending on the model) by the way. They back up their high price. But there are lots of good options. A Mag 24 would be another one.

You can use that height and flow target to select any pump that has a published flow curve and get a reasonably accurate prediction of the actual flow you will get.

Tip: Use a head loss calculator - not just a height estimate - if you're doing anything fancier than a basic return. Elbows and manifolds eat lots of flow....generally not recommended to use any of them if possible...a minimum, as needed. Where possible, use separate pumps for things like reactors and refugiums.