Sump questions. 3D printing?

MichelleRay · Mar 1, 2018

I've been looking into possibly adding a sump to my 55g so I can move some equipment out of my way. I've got a 20g long aquarium gathering dust right now and it will fit in my stand, so I am probably going to convert that. I was looking at kits to get the baffles for it but the prices all seemed a little silly to me, especially given the fact I can print anything I want already. So here is the question on this. Given that I can design them basically any way I want, are there better designs than the standard solid walls? Anything that would increase the usefulness or effectiveness?

The rest of my questions are more general. Mainly I'm concerned about overflow. (who isn't right?) Is it possible to make a watertight sump? I was thinking maybe a container with a lid for the whole structure which could be closed down tightly using a rubber seal. A cutoff would have to be placed in the intake to allow maintenance and such, but otherwise I think this might be possible? Something like this is what I'm picturing, with baffles inside to direct water flow and water hook-ups for pipes on each end:
https://images-na.ssl-images-amazon.com/images/I/71nIw4OTpVL._SL1500_.jpg

Assuming the above is not possible or feasible, what can be done to ensure that, should the power go off, the sump won't overflow and flood my house? I read somewhere about putting a pinhole in the intake, but I'm not 100% clear on the anatomy of sump plumbing. I can't seen to find a simple drawing to show the design and water flow, and the pictures I've seen have only given me a murky idea of how to proceed. I'd like to find some clear instructions if anyone can point me in the right direction?

DLHDesign · Mar 1, 2018

Note that if you want to print anything, it'll likely need to be in ABS - PLA will break down relatively rapidly.

A watertight sump is called a "canister filter". These exist, but I don't know many reefers using them. A big benefit of a sump is that you increase your gas exchange (more surface area, water cascades, equipment like a skimmer, etc.). You would not get that with a canister style of filter, of course.

In terms of the overflow; the goal is to set things up so that the sump can hold more than will drain out of the DT (display tank) when no power is on. This is why most tanks are drilled in the back (or side) and not the bottom (or, if they are bottom-drilled, they have a stand pipe that reaches up to the water's surface). The idea is that the pump in the sump is what causes the water level in the DT to rise up enough to reach the drain. When the pump turns off, some water drains out (which the sump needs to handle), but not the entire DT.
The pin hole you've heard about is an method of creating a syphon break. The idea is that the return nozzle (where the water from the pump comes out) may be low in the tank. So low that if you turn off the pump, the resulting syphon that is created would cause the DT to drain more than desired (potentially flooding things). Rather than move the nozzle up (because flow is desired low in the tank, for example), a "syphon break" is used. The pin hole is the simplest of these and involves... well; literally making a hole in the pipe. This hole would be located at or above the desired drain point (keeping in mind that the hole will spray out some water when the pump is running, so usually below the water line). Then when the pump is turned off and the hole is exposed to air, the syphon breaks at that point rather than when the nozzle is exposed. (Note that such holes are generally larger than an actual pin, since that small of a hole would easily clog and be tough to clean out.)

As far as sump plumbing pictures - there are plenty of them scattered throughout the Member Tanks forums (and likely beyond). Browse around for a bit in there and you should see plenty of options (and there are many). And if you find something you like, you can ask the person who has it any questions you may have (though feel free to ask here as well; we're all always happy to help!).

MichelleRay · Mar 2, 2018

I've seen canister filters but I had no idea you could put your equipment into them. I assumed they were just for filtration. I'll check into them!

laverda · Mar 2, 2018

MichelleRay said:
I've been looking into possibly adding a sump to my 55g so I can move some equipment out of my way. I've got a 20g long aquarium gathering dust right now and it will fit in my stand, so I am probably going to convert that. I was looking at kits to get the baffles for it but the prices all seemed a little silly to me, especially given the fact I can print anything I want already. So here is the question on this. Given that I can design them basically any way I want, are there better designs than the standard solid walls? Anything that would increase the usefulness or effectiveness?

The rest of my questions are more general. Mainly I'm concerned about overflow. (who isn't right?) Is it possible to make a watertight sump? I was thinking maybe a container with a lid for the whole structure which could be closed down tightly using a rubber seal. A cutoff would have to be placed in the intake to allow maintenance and such, but otherwise I think this might be possible? Something like this is what I'm picturing, with baffles inside to direct water flow and water hook-ups for pipes on each end:
https://images-na.ssl-images-amazon.com/images/I/71nIw4OTpVL._SL1500_.jpg

Assuming the above is not possible or feasible, what can be done to ensure that, should the power go off, the sump won't overflow and flood my house? I read somewhere about putting a pinhole in the intake, but I'm not 100% clear on the anatomy of sump plumbing. I can't seen to find a simple drawing to show the design and water flow, and the pictures I've seen have only given me a murky idea of how to proceed. I'd like to find some clear instructions if anyone can point me in the right direction?

If you 20 long is glass go to any hardware store and have them cut some glass for you. If it is acrylic then go to a plastic supply and do the same. Get the proper bonding agent (WeldOn) while there. Most people add more baffles then needed. To be honest you really do not have to have baffles in your sump.

The only things I think you would want to print for your sump would be possibly probe holders. ATO switch holders and holders for and dosing lines.

A sealed sump is going to be all but impossible to do and defeats the purpose of a sump. A properly designed sump, tank combo and built as zero chance of overflowing normally.

The water level in the sump should always below the maximum the sump will hold to allow for power outages. You can determine the maximum running level by filling your tank with the power off. Keep filling the display letting the water drain down until your sump is an inch or so from the top. Mark the water level in your sump. This is your maximum water level with power off. Plug your return pump in to a power strip with a switch so you can quickly and easily turn you pump on or off if need be. Then turn on your return pump while watching the water level in your display tank. Let it run for a few min and then mark the water level in your sump again. This mark will be you maximum water level while your tank is running. I would then take a gallon or so of water out of the sump return pump section and mark the water level again. This will by your low water level mark.

How your return lines are plumbed can have a big effect on how much water will drain to your sump in a power outage. If they are much below the surface of the water more water will drain. That is why siphon brakes are added. After making your marks give your system a full test. Then add the gallon of water you removed and test again.

laverda · Mar 2, 2018

MichelleRay said:
I've seen canister filters but I had no idea you could put your equipment into them. I assumed they were just for filtration. I'll check into them!

You can’t. DHLDesign was just saying if you could seal a sump it would in essence be a canister filter. Canister filters really are not suited for reef tanks. They do a great job of removing excess food and detritus from the water column, however it is still in your system. Unless you clean it more the weekly they become nitrate and phosphate factories as everything they capture brakes down inside them. I would only recommend a canister filter for when doing tank maintainence or to run carbon.

DLHDesign · Mar 2, 2018

laverda said:
DHLDesign was just saying if you could seal a sump it would in essence be a canister filter.

Right - exactly. Sorry if I confused things for you, @MichelleRay. I agree with the above; canister filters aren't a good match for long-term reef success (not without significant effort).