Need Some Drain & Sump Wisdom

[RandyC]

I'm not following the logic here. Why wouldn't I want the larger drain as the primary?

A 1/2” pvc pipe that’s gravity fed (no pressure) only supports around 420gph. If your main drain (assuming that you used the larger for the gated drain) were to ever clog, you’d have a good chance of that drain not being large enough to handle the flow and then water all over the floor.

Under normal circumstances and a moderate flow rate for that tank, using the 1/2” drain for the main drain should be enough, then you wouldn’t have to worry about the cases where the main drain clogged since the emergency drain is plenty large (the 1.5” middle one). But that being said, 1/2” isn’t that big and if you ever wanted a large tank turnover (say 10x or more) that 1/2” drain wouldn’t be enough.

Edit: Oh and an answer to one of your other questions. A single drain in my book is never, ever ok.

 

[MichaelB]

Amazed by all the responses here, I'm learning alot just following along.

 

[MarcosDelgado0]

Amazed by all the responses here, I'm learning alot just following along.

Soak it all in so you can put it all to use when you plumb the low boy lol! I’m not looking forward to my own plumbing… worst part of setting up a tank!

 

[ReyDeFarts]

I like the modular marine ones. But yes they are expensive. I don’t have experience with the other ones so I can’t speak on them, but the Synergy Reef Shadow Overflow was my second option

I was looking at the Synergy reef systems recently for another possible build. Slick looking!

If I go down this road, how much flow should I realistically aim for?

For the price of those overflows, I'm starting to think I like the idea of using the 3 existing holes for the bean animal. Then just drill a couple returns on each side.

A 1/2” pvc pipe that’s gravity fed (no pressure) only supports around 420gph.

Ignorance has my mind going in circles. Would it be feasible to combine both 1/2" as primary and leave the large for the emergency? Essentially getting me nearly 800gph of drainage? I'm not sure if that's a bad idea or not.

 

[MarcosDelgado0]

I was looking at the Synergy reef systems recently for another possible build. Slick looking!

If I go down this road, how much flow should I realistically aim for?

For the price of those overflows, I'm starting to think I like the idea of using the 3 existing holes for the bean animal. Then just drill a couple returns on each side.

Ignorance has my mind going in circles. Would it be feasible to combine both 1/2" as primary and leave the large for the emergency? Essentially getting me nearly 800gph of drainage? I'm not sure if that's a bad idea or not.

They do look nice!

I use a Jebao DCP 3500 on a 50 Gallon Lowboy with a 31 gallon sump, bean animal 3- 1” drains.

Using your existing 3 holes as drains and drilling returns would be the cheapest route forsure. Is there better options? Sure. But this would be the cheapest route. Personally I probably would’ve gotten annoyed figuring out the metric stuff and just patched the holes and did an external overflow and drilled returns

 

[ReyDeFarts]

Personally I probably would’ve gotten annoyed figuring out the metric stuff and just patched the holes and did an external overflow and drilled returns

LOL... it isn't THAT bad! Dramático...

But yeah, I think I would prefer doing the external overflow. Just have too many other expenses that are far more important than spending a bunch on this tank.

 

[richiev]

Is there any particular reason a sump being more than low flow matters? I've never really understood the practical implications of it, especially if you normally skim lightly or even part of the day.

I'd think the most relevant part would be if you're cool with more in tank pumps, which is good anyway because they're more efficient and dispersable. The second would be making sure it's fast enough that floating particulates get sucked down the overflow, but I'd think enough in tank flow would give that anyway.

Is there any real science saying why flow rates matter? Too high is bad because it sounds like a waterfall. If you had incredibly low it'd eventually be as if there was no sump. However if you have a constant, quiet, flow, what's the actual downside?

Separately, I've patched the bottom of a tank before with a ton of silicone and a small piece of glass. However, that was a tank going in a basically outside place over tile. The idea of having my display with holes in the bottom I patched in my house would... not make me sleep well.

 

[MarcosDelgado0]

LOL... it isn't THAT bad! Dramático...

But yeah, I think I would prefer doing the external overflow. Just have too many other expenses that are far more important than spending a bunch on this tank.

I get stressed out easy haha! You’re better than me. My lowboy was supposed to be a “budget build” and I put more money into it than I would’ve liked. And now I’m upgrading after only a few months smh. That’s good you have your priorities straight, stick to your budget! The good thing about this hobby is there’s a lot of ways to do something and make it work

 

[RandyC]

I was looking at the Synergy reef systems recently for another possible build. Slick looking!

If I go down this road, how much flow should I realistically aim for?

For the price of those overflows, I'm starting to think I like the idea of using the 3 existing holes for the bean animal. Then just drill a couple returns on each side.

Ignorance has my mind going in circles. Would it be feasible to combine both 1/2" as primary and leave the large for the emergency? Essentially getting me nearly 800gph of drainage? I'm not sure if that's a bad idea or not.

I wouldn’t combine, as in connecting them to a tee, but as others have said, you could set that up as a bean animal (three drains - siphon, trickle and e-drain) and be okay. But then you have to come over the top or drill for the returns. Me personally, I hate the look of over the top return lines. Also, I like not having a fat internal overflow box taking up tank real estate.

 

[ReyDeFarts]

Separately, I've patched the bottom of a tank before with a ton of silicone and a small piece of glass. However, that was a tank going in a basically outside place over tile. The idea of having my display with holes in the bottom I patched in my house would... not make me sleep well.

It would be inside the house...on tile! So I'd sleep fine! Haaa haaa.

I definitely get what your saying though. For some reason, I have a weird appreciation for silicone. It's holding and sealing power that is.

 

[RandyC]

It would be inside the house...on tile! So I'd sleep fine! Haaa haaa.

I definitely get what your saying though. For some reason, I have a weird appreciation for silicone. It's holding and sealing power that is.

Is there any particular reason a sump being more than low flow matters? I've never really understood the practical implications of it, especially if you normally skim lightly or even part of the day.

I'd think the most relevant part would be if you're cool with more in tank pumps, which is good anyway because they're more efficient and dispersable. The second would be making sure it's fast enough that floating particulates get sucked down the overflow, but I'd think enough in tank flow would give that anyway.

Is there any real science saying why flow rates matter? Too high is bad because it sounds like a waterfall. If you had incredibly low it'd eventually be as if there was no sump. However if you have a constant, quiet, flow, what's the actual downside?

Separately, I've patched the bottom of a tank before with a ton of silicone and a small piece of glass. However, that was a tank going in a basically outside place over tile. The idea of having my display with holes in the bottom I patched in my house would... not make me sleep well.

No scientific evidence as with anything else in our hobby, but I’m sure there’s some magic number that if you don’t have enough turn over in your sump (with dependence on DT to sump size) that your skimmer won’t be as efficient, heaters will have to work harder, fuges won’t work as well, and you might create some anaerobic areas in your sump.

I wouldn’t be scared as long as the appropriate sized thickness of glass is used. I’d be more nervous about having a closed loop return system with bulkheads in the bottom than putting a piece of glass over holes with silicon.

 

[richiev]

It would be inside the house...on tile! So I'd sleep fine! Haaa haaa.

I definitely get what your saying though. For some reason, I have a weird appreciation for silicone. It's holding and sealing power that is.

I'd just run it standard if it were me. Really hard to change later, but if it's a low flow zoa tank, it's already low flow, sooo..

I'd put a cheap ball valve on each drain and just play with both until you get it quiet. In my experience variable DC pumps aren't controllable enough to fine tune a drain and you'll end up playing with both to get it right. Make sure to not oversize your pump, since DC pumps can't run at 1% of their max. They all have a minimum, which in my experience is more like 30-40%.

Regarding overflow risk and which to do. I'd check out your sump. Drain or return clogs are a problem, however they're a minimizable one.

If your sump is big enough, it's impossible for your sump to overflow onto the floor if you have an overflow in your tank.

Similarly, if your return section of the sump is sized small it can completely or almost completely avoid overflowing the display. The main issue possibly being your powerheads cause a really full tank to spill over. You can also reduce the risk of that, by reducing the water volume in the return section. A trick I've used is put live rock in that return section. A pump isn't going to suck up a rock, so that effectively reduces the return water volume by displacing water out.

I'd try and start by seeing if I could get things quiet and happy using the smaller as my main drain, but if I couldn't.... Well I wouldn't probably setup a 3rd drain and drill more return holes personally.

 

[richiev]

No scientific evidence as with anything else in our hobby, but I’m sure there’s some magic number that if you don’t have enough turn over in your sump (with dependence on DT to sump size) that your skimmer won’t be as efficient, heaters will have to work harder, fuges won’t work as well, and you might create some anaerobic areas in your sump.

I’d wouldn’t be scared as long as the appropriate sized thickness of glass is used. I’d be more nervous about having a closed loop return system with bulkheads in the bottom than putting a piece of glass over holes with silicon.

Would be interesting for someone to do the math or find research on the first part. The heater point is interesting, though mitigatable if you put at least one heater in a tank. That's something I feel we all should be doing anyway, unless we have multiple return pumps, but none of us (including me) seem to do so. Pump dies, no heating.

Regarding nutrient export, I think that's what folks say I just don't fully grok it being true. At infinite slowness (fully stopped sump), certainly the skimmer and fuge and ... do nothing. However if you have some flow, then worst case the sump has a lower level of dissolved stuff than the display. Let's say 10 units of gunk in the display to 1 unit of gunk in the sump.

At infinite fastness, the sump and the display have equal amounts of everything.

At what point is it close enough, or even functionally equivalent? Intuitively it seems like it'd be a lot closer to 1x turnover, but I have no justification to say why I just don't think a skimmer can pull out 100% of everything in an hour. If it's not pulling everything out, then isn't it the sump going to be pretty close to the display numbers anyway?

 

[RandyC]

Similarly, if your return section of the sump is sized small it can completely or almost completely avoid overflowing the display. The main issue possibly being your powerheads cause a really full tank to spill over. You can also reduce the risk of that, by reducing the water volume in the return section. A trick I've used is put live rock in that return section. A pump isn't going to suck up a rock, so that effectively reduces the return water volume by displacing water out.

This assumption only works if you have no more water coming into the sump. If the main drain clogs, but the emergency drain is not sufficient to handle the flow, water will flow out of the display tank while still putting water into the sump.

I'd put a cheap ball valve on each drain and just play with both until you get it quiet. In my experience variable DC pumps aren't controllable enough to fine tune a drain and you'll end up playing with both to get it right. Make sure to not oversize your pump, since DC pumps can't run at 1% of their max. They all have a minimum, which in my experience is more like 30-40%.

Cheap balls valves will seize up or will be incredibly difficult to turn eventually. If you’re going to go ball valve, at least use a true union ball valve that can be removed to be cleaned and greased or replaced.

I personally wouldn't go ball valve and I wouldn’t set up a bean animal on this size tank. But admittedly, if there’s one thing I’m OCD about, it’s plumbing.

 

[richiev]

This assumption only works if you have no more water coming into the sump. If the main drain clogs, but the emergency drain is not sufficient to handle the flow, water will flow out of the display tank while still putting water into the sump.

I'm not sure I follow. Describing two cases:

First, assume the drains are all completely shut off. One can size a return section to only hold that much. Let's assume someone does that.

Second, let's assume the first is true, it can't overflow with the drains plugged, but let's imagine some water is draining. Any water coming into the sump comes from the display. If you dump 1 cup from the display into the sump, then the return will get one cup of water in it, which it will then push back into the display. At that point you're back to the first case.

Repeat an infinite number of times at small amounts (a drain slowly draining) and it similarly can't overflow.

The other things can happen though (low turnover and maybe a temp delta at high clog levels, a return pump having issues from running drier than it should, ...).

Cheap balls valves will seize up or will be incredibly difficult to turn eventually. If you’re going to go ball valve, at least use a true union ball valve that can be removed to be cleaned and greased or replaced.

I personally wouldn't go ball valve and I wouldn’t set up a bean animal on this size tank. But admittedly, if there’s one thing I’m OCD about, it’s plumbing.

I similarly would union things just to make it easy to take apart some day. I have gate valve on some tanks and went a cheap Ace Hardware ball valve on my frag tank. It's harder to turn, but I can adjust rates with my DC pump so it's been ok in my experience. Worst case I give it an ugga-ugga level of turn, overshoot, and recorrect

 

[RandyC]

I'm not sure I follow. Describing two cases:

First, assume the drains are all completely shut off. One can size a return section to only hold that much. Let's assume someone does that.

Second, let's assume the first is true, it can't overflow with the drains plugged, but let's imagine some water is draining. Any water coming into the sump comes from the display. If you dump 1 cup from the display into the sump, then the return will get one cup of water in it, which it will then push back into the display. At that point you're back to the first case.

Repeat an infinite number of times at small amounts (a drain slowly draining) and it similarly can't overflow.

The other things can happen though (low turnover and maybe a temp delta at high clog levels, a return pump having issues from running drier than it should, ...).


I similarly would union things just to make it easy to take apart some day. I have gate valve on some tanks and went a cheap Ace Hardware ball valve on my frag tank. It's harder to turn, but I can adjust rates with my DC pump so it's been ok in my experience. Worst case I give it an ugga-ugga level of turn, overshoot, and recorrect

If only the main drain is clogged, then all water will go down the emergency drain. But if the emergency drain is too small to handle the flow, what extra water is not drained will eventually flow out of the display tank, meanwhile, some water is still draining into the sump. That water will continue to flow into the sump and then the return compartment. Eventually, the return compartment will run out of water, but not before some amount (not the full amount - this will depend on size of sump) of the volume of the sump overflows out of the display tank.

 

[Coral reefer]

I think flow rate through the tank/sump is a relic of when people used wet dry filters for bacteria I. The sump. I don’t think it matters much at all anymore

 

[derek_SR]

I think flow rate through the tank/sump is a relic of when people used wet dry filters for bacteria I. The sump. I don’t think it matters much at all anymore

I was going to say the same thing, I think it matters very little. If anything, I'd try to get semi-close to the volume your skimmer is pulling just to make sure you're maximizing that efficiency, but even then it doesn't really matter - just means you could probably get away with a smaller skimmer at the lower flow rate.

There are other side effects - you may want high flow through the sump to improve aeration, or for refugium purposes, etc. And I think more return flow clears water up slightly faster after feeding...but again, hardly that important or worth worrying too much about IME.

 

[Srt4eric]

I’d use all 3 holes for a beam animal setup

Yea you would...

 

[PjFish]

I’d make it two drains and a return, but the largest should be the emergency drain. The emergency drain should always be able to handle the entire flow of the tank and I don’t think that 1/2” drain would be enough for that. If you have enough space to get a larger bulkhead in on the right hole (from top view), I’d drill and make that hole bigger.

But to be honest, if it was me, I’d rip out that internal overflow and gain some real estate back for livestock. Cover those holes with a piece of 1/4” glass and silicon and then drill in an external overflow and two 3/4” returns.

But hey, I like DIY projects setting up new tanks.

Lol most all these ideas are being repeated from the original thread of this tank plus a few more ! Just make sure the sump can handle the back syphon and tank handle clogged return! Can always have return pump connected to float switches/ magnetic sensors one in sump other in display that turns return pump off for low water in sump and high flood levels in display.. just keep it a simple low maintenance tank..slow flow in sump and whatever or how many power heads you want in the display! You can always modify down the road since its not that big of tank but guess thats opinionated perspective!