OVERFLOW BOX HOLE?

[Andrés Garza]

> Hello everyone, good morning.

I currently have a 55-gallon display tank, and I’m planning to drill it to install a bulkhead. Given the limited size of the system, I’d prefer to avoid drilling two separate holes for both the main drain and return line. Instead, I’m considering using an Eshopps Eclipse overflow box.

I’d appreciate some insight into how these overflow boxes function in practice and whether they’re a good fit for a smaller setup like mine.

My plan is to drill a single 1-inch hole to serve as the main drain and connect it to the Eclipse box externally. In this configuration, what would be the practical differences compared to running all the PVC plumbing externally without an overflow box?

In terms of reliability, noise reduction, and flow stability, would the Eclipse overflow box be a superior solution for this type of setup?


The image is from the internet and is for reference only.

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[Entropy]

Not sure I understand the first part. You don't really need to drill a hole for a return line as you can just run it over the back of the tank. You can actually run as many return lines as you want (until you run out of room at least). The Eclipse comes with a 1.5 inch hole saw for the Small and Medium version. I have never personally run one, but my LFS has several and they all seem to work great and are near silent with the Herbie style drain setup.

On a bizarre note, I am terrified of having an external overflow even though in theory they are safer than an internal overflow. If the external fails, you can only drain to the height of the internal weir. Even if the weir fails, you can only drain to the bottom of the bulkhead hole. On an internal overflow box with holes at the bottom of the tank you can still only drain to the weir level, but if the weir (internal box) fails you can drain to the lowest standpipe or worst case the whole tank. So even though the external is in theory much safer, my brain screams "don't do it!". I think what turns me off the most is that I like my tanks flush against the wall and an external setup does not allow that. Of course, my brain also doesn't understand while huge jets fly and why boats will a hole in the middle still float.

 

[wvned]

Here is how I drilled my 75 gallon. The small holes are the returns and the large one is used to mount the overflow.
The picture you posted above shows 2 drains coming from the overflow box and one has a valve. The valve is used to make the drain quiet. Inside the box the entry to the main drain is below the water and runs without air in it. The valve is used to slow the amount of water in the drain until it can run with a siphon air free. This makes it quiet. The second drain is the emergency drain is the first gets clogged.

The diamond bit for the large hole comes with the overflow kit.

Before

After

I was building an eel tank and I wanted the ability to tightly close the top.

 

[Andrés Garza]

Here is how I drilled my 75 gallon. The small holes are the returns and the large one is used to mount the overflow.
The picture you posted above shows 2 drains coming from the overflow box and one has a valve. The valve is used to make the drain quiet. Inside the box the entry to the main drain is below the water and runs without air in it. The valve is used to slow the amount of water in the drain until it can run with a siphon air free. This makes it quiet. The second drain is the emergency drain is the first gets clogged.
View attachment 32414643
The diamond bit for the large hole comes with the overflow kit.

Before
View attachment 32414644
After
View attachment 32414645
I was building an eel tank and I wanted the ability to tightly close the top.

Here is how I drilled my 75 gallon. The small holes are the returns and the large one is used to mount the overflow.
The picture you posted above shows 2 drains coming from the overflow box and one has a valve. The valve is used to make the drain quiet. Inside the box the entry to the main drain is below the water and runs without air in it. The valve is used to slow the amount of water in the drain until it can run with a siphon air free. This makes it quiet. The second drain is the emergency drain is the first gets clogged.
View attachment 32414643
The diamond bit for the large hole comes with the overflow kit.

Before
View attachment 32414644
After
View attachment 32414645
I was building an eel tank and I wanted the ability to tightly close the top.

I am planning to drill a single 42 mm bulkhead for a downpipe in my 200-litre aquarium, with a slight slope directing water flow toward the sump. In your experience, would a single downpipe be sufficient for reliable drainage, or is it advisable to use an overflow box with dual downpipes to include a backup/safety drain? Considering the relatively modest volume of the tank, I am trying to determine whether a redundant safety line is necessary or if a single properly sized downpipe would provide adequate performance and security.



---product specifications :
Exterior Dimensions - 4.7" L x 4" H x 2" W

Max Flow - 660 GP

Drain Hole Size Required - 41.5mm - 44mm (we suggest using our 42mm Glass Drill Bit)
Drain Plumbing Size - 40mm or 1.5" Soft Tubing
Return Hole Required Size - 27mm - 32mm (we suggest using our 30mm Glass Drill Bit)
Return Plumbing Size - 23mm or 3/4" Soft Tubing

What's included?
1x INOUT External Box
1x INOUT Internal Grid
2x Bulkhead Nuts
2x O-Rings
1x Spare Return Nozzles
1x Drilling Template

 

[wvned]

The largest tank I have used a single line on is a 30 gallon cube. It worked fine.

I think the INOUT would be an excellent choice.

 

[Andrés Garza]

The largest tank I have used a single line on is a 30 gallon cube. It worked fine.

I think the INOUT would be an excellent choice.

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I’m planning the overflow setup for a 55-gallon tank and I’m wondering about the drainage capacity. Would a single 45 mm downpipe be sufficient for this volume, or is it safer to go with a larger 60 mm bulkhead combined with an Eshopps overflow box, including a primary and a safety drain (Q-inch drop)? I’m trying to determine if the simpler setup would handle the flow reliably without risking overflow.


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[wvned]

After reading. The INOUT reguires you to drill 2 holes of different sizes. The Eshopps only requires one and comes with the bit.
For saltwater you would only need 300GPH - I am not metric, sorry err 1200LPH
You do not have to have 2 drains. I dont on tanks on concrete floors that cant ruin anything. Yes I have had them overflow when the drains plug. Usually from macro algae.

 

[Entropy]

How much flow do you plan to push through the overflow is probably the most important thing, but I can't imagine you pushing 3400lph through your sump. If my fuzzy math is correct, that would be 16 times turnover through the sump. I think desired is more like 5 times.

45mm hole = 26mm pipe = ~3400lph
60mm hole = 32mm pipe = ~5700lph

 

[griss]

The eShopps is very easy to install and I've been using mine only utilizing one of the drains (the other I capped off) on my 40 gallon for years with no issues. The only downside for the eShopps, IMO, is they are not designed for traditionally braced (black plastic frame) tanks and, as a result, the internal part sits low in the water and I had about 1/4 inch lower water than I wanted. I fabricated an adjustable weir out of plexiglass and nylon nuts/bolts and was able to raise the water level in the tank.

Post in thread 'New Acrylic aquarium - I'm back after 30 y.'

Mar 16, 2024

Griss one question for you about Eshopps Eclipse overflow that i have. Whats the problem of level and how to adjust it - did need to drill more up or down from top as on top i have a stronger supports see photo? Thanks.

So, I was installing it on a traditionally braced (plastic brace). The instructions were not clear that if drilling a braced aquarium to put the hole/drill template on the inside.

As a result, my overflow sits a bit low and the water level was about 1/4” (6.35mm) below the bracing.

• griss