Help with overflow setup

[TheWhiteFang]

Hello, I originally posted this in the Reef Aquarium Discussion forum, but I think I probably should have posted it here first. My idea was to find an external overflow box that would fit the current cutout for the bulkhead, but I have not had any luck. I am unsure how bulkhead size works, but I just measured the pvc running down and it is 1" in size.

Hello,

I am very new to the hobby and got a 40 gallon tank from my LFS that is a bit older. I have had a few instances where a snail blocks my overflow and my tank starts to fill. I haven't had it yet, but I am very concerned/anxious about the overflow not having a failover. Is there a newbie-friendly way to fix this?

Overflow goes into sump. I believe the pipe is 3/4", not sure what the size of the hole the bulkhead goes into is.

I also created a diagram for how the setup is currently flowing:

 

[Dom]

I understand your concern; you always want to have a second drain line for emergencies.

If your plumbing is one inch, then you use 1 inch bulkheads.

I'm not sure I am understanding what you are asking us though. But based on your diagram, I wouldn't use a gate valve on your drain line. To control flow, I would install my gate valve on my return line.

Are you asking how to add a second emergency line? Are you asking what you can do to prevent the snails from blocking you drain?

Lets get clear so we can get you going.

 

[TheWhiteFang]

I understand your concern; you always want to have a second drain line for emergencies.

If your plumbing is one inch, then you use 1 inch bulkheads.

I'm not sure I am understanding what you are asking us though. But based on your diagram, I wouldn't use a gate valve on your drain line. To control flow, I would install my gate valve on my return line.

Are you asking how to add a second emergency line? Are you asking what you can do to prevent the snails from blocking you drain?

Lets get clear so we can get you going.

So this is how the tank came set up. My goal is to add an emergency line for my peace of mind while also ensuring that I don't mess anything else up in the process (re-drilling the tank makes me nervous).

I was looking at the ESHOPPS Eclipse Overflow or the Fiji Cube External Overflow Box, but am still a bit confused about sizing and how to tell if either of these will fit my current cutout.

 

[Dom]

So this is how the tank came set up. My goal is to add an emergency line for my peace of mind while also ensuring that I don't mess anything else up in the process (re-drilling the tank makes me nervous).

I was looking at the ESHOPPS Eclipse Overflow or the Fiji Cube External Overflow Box, but am still a bit confused about sizing and how to tell if either of these will fit my current cutout.

But do those overflows do not really address your concern. While you have two drain lines from the overflow, you still only have one exit from the tank. If that gets blocked, you'll still have a flood, no matter how many drain lines you have in the overflow.

I don't see any other way other than drilling the tank.

You could install something like this and not use the internal overflow at all: Amazon product

Or install it and use all 3 lines.

 

[TheWhiteFang]

But do those overflows do not really address your concern. While you have two drain lines from the overflow, you still only have one exit from the tank. If that gets blocked, you'll still have a flood, no matter how many drain lines you have in the overflow.

I don't see any other way other than drilling the tank.

You could install something like this and not use the internal overflow at all: Amazon product

Or install it and use all 3 lines.

My thought is that the smaller internal footprint of the external paired with a lid would make it much more difficult for inverts/fish to get into the overflow in the first place. My current internal overflow box is 6"x4" with the single pipe for overflow that is at a 90 degree angle which is not optimal. I designed/3dprinted a lid for my current overflow to see how it works as a solution. If this works at keeping the livestock out, then I think that having the external with the emergency overflow would be a really good solution.

I will try and measure out the current cutout to get the exact size of it, and if I end up having to drill I guess I could always opt for one of the externals that have 2 cutouts.

I have considered the HOB style overflow, but they seem to get very mixed reviews due to siphon breaks causing the flow to stop.

 

[TheWhiteFang]

Update: I ended up going with an external overflow. I had to drill out the hole that existed (which was terrifying), but all went really well. Thank you everyone for the advice. I appreciate it :)