How to setup a sump when the bottom is drilled but no overflow boxes?

[parttimer]

As the title states, I bought a used tank that was drilled in the bottom, I had no intention to use a sump, I was running a canister. We purchased a fish that was getting beaten up by an original tank inhabitant. Someone suggested putting the fish in the sump for a few days to give the other tankmate a chance to setup house. I purchased a ton of plumbing and a used sump. Got everything flowing but I am fighting the balance of flow to the sump, flow back up and preventing too much water coming down when the pump is off. I have a 1" main drain going to my sump, I tried setting it up as a herbie but that was very noisy unless i put the drain very low in the tank, but in a power outage I'd overflow the sump. Then tried a durso but I can't get the vacuum to break when I turn the pump off, even with a hole in the cap. I understand most of these setups are usually in a sealed overflow, which I don't have. The pump I have is adjustable and even on the lowest setting can almost out pump the flow coming to the sump.

 

[cvrle1]

This may not work for you, depending on what you have in your display tank. If you can drain it and plug those holes at the bottom, that would be the way I would go. I removed dual overflows in the tank I was going to originally use, and had 4 holes at the bottom. I cut out square pieces of glass and siliconed them on top of each hole. For good measure, I did same on the bottom as well. I tested if for several weeks and it was dry as it could be. Really easy and fast to do, as long as you can empty your tank out.

Then you can get proper overflow box and get it all sorted out. Would be easier and faster most likely than to mess around with what you have now.

 

[BeejReef]

It's hard to envision. You're saying you have a 1" pipe fitted to a bulkhead in the bottom of the tank that rises up some distance to near the surface of the water?

If so, how does the pipe fit into the display tank side of the bulkhead? Slip fittings are probably the most common. I'd not want that style of fitting outside of a sealed overflow box though just bc in a 12 hour power outage and no return pump, the dt may continue to slowly dribble into the sump.

You must have a very robust return pump. Not many can overwhelm a 1" pipe pulling a full siphon. Being honest, I don't think you'll be happy with a single overflow standpipe setup over the long haul. That said, simply downsizing your return pump might be an interim solution. Less water being pumped up means less that has to overflow = less noise if you're forced to extend it near to the water surface to prevent a sump overflow. You may even find that you're able to get the siphon to break with less flow.

If your return pump is soft plumbed (not pvc), you may be able to test the scenario by just using a pair of channel locks or pliers to restrict the flow.

 

[parttimer]

The top fittings are threaded, so the "overflow" pipe is threaded. I redid a section of the overflow and seem to have flow matched the drain with the pump. I think I'm sitting at 60% of the pump with the 1" running wide open. The second drain I have set higher up in the tank in case the first clogs. I'm sure it's a mess of a hybrid setup! I am debating on putting a hole in the side of the elbow below the water level but above the point my sump would overflow to see if that breaks the syphon. I was debating adding a valve on the return line, which is soft plumbed to add some head pressure to cut back on the flow. I'll try to get pictures to better show. Maybe someone can just help clean it up!

 

[BeejReef]

If you can grab a pic, that would def help. If you only have one hole in the bottom of the tank and one bulkhead, I think that is you're issue. You may be able to fiddle with flow rates and strainers and pump settings to hold a desired water level in the DT, but you'll never be able to break the siphon above the lowest opening in your overflow pipe.

Also, without a sealed overflow, you're forced to run your primary or emergency that much closer to the surface where it is noisy because of all of the water volume from the top inch or so of the entire tank that can drain into the sump.

Lastly, keep in mind that the flow of your return pump is not a constant. They can have good days and bad days depending on temperature, how clean the intake is, snails, algae, u name it. You don't want a scenario where you're away from the tank for a day, the return pump slows down and your dt drains down three or four inches. Even if it doesn't overflow your sump, you powerheads will be throwing salt spray and water all over the room as they churn half out of the water.

Salinity swings can also come into play with a wandering water level if u run an ATO.

That's why the most common answer to a single drain is to learn to love the noise of a surface siphon, or do drain it down and make an upgrade.

 

[parttimer]

So, these are my drains, the right side is the normal drain, it's 1" all the way down, it has a shutoff that goes directly to the sock in the sump. The left side is 3/4" and the emergency side that has the flex pipe that goes to the sump. The top of the emergency drain is drilled in the cap. The normal drain, if i drill a hole I don't seem to get the volume to the sump, so I think I will pop a small hole in the side of the elbow below the water level so in the event of a power issue the syphon will stop. Does that make sense?