Internal vs External Overflow

[samnaz]

I'm in the process of setting up a 30 gallon long rimless with a 20L DIY sump.

I'm tempted to go the HOB overflow route simply because it's the easiest, and I find plumbing to be the most uninteresting, complicated, and not fun part of a reef tank. Perhaps that is because I know nothing about the subject. I try but it goes in one ear and out the other.

If I go the internal overflow route, what supplies does that require? A drill and diamond coated bit, overflow box....what else? How many and what size holes, bulkheads, tubing, silicone, glue? What gph should the pump be?

Help me understand!

(I don't care how loud it is, so long as it's semi-easy to construct, leak and flood proof, and inexpensive is good too. The tank will be mostly LPS... if that makes a difference.)

 

[Daddy-o]

First, is your tank glass tempered?

 

[samnaz]

First, is your tank glass tempered?

No it's not.

 

[samnaz]

Anyone?

 

[JSchwarz]

I believe if you have the option to drill the tank you will be kicking yourself later if you don't. HOB overflows have a far higher chance of failure and just don't look as good.

I also have a 30 gallon with a 20l DIY sump. I used an eclipse small internal overflow that comes with a holesaw and template. I used a 1/2 inch return (3/4 would've been fine). For the return I just pieced together what I needed on BRS. They list and sell the holesaw you need for whichever bulkhead you get. My return pump is a sicce syncra 1.5 (357gph).

For the plumbing I used pvc from the return and overflow and had it switch to soft line under the stand. I have a ball valve on the primary drain (should've used a gate valve like everyone said).

There is also glass-holes that sells kits for all the pieces. It can also give you an idea of all the pieces you would need.

With this setup I don't have to worry about the sump overflowing from back siphon as the return is high enough and the sump is big enough to handle the water. I also don't have to worry about the siphon restarting on the overflow like with a HOB. I made the return section of the sump small enough that even if the overflow got clogged somehow, the return would run dry before overflowing the tank.

 

[samnaz]

I believe if you have the option to drill the tank you will be kicking yourself later if you don't. HOB overflows have a far higher chance of failure and just don't look as good.

I also have a 30 gallon with a 20l DIY sump. I used an eclipse small internal overflow that comes with a holesaw and template. I used a 1/2 inch return (3/4 would've been fine). For the return I just pieced together what I needed on BRS. They list and sell the holesaw you need for whichever bulkhead you get. My return pump is a sicce syncra 1.5 (357gph).

For the plumbing I used pvc from the return and overflow and had it switch to soft line under the stand. I have a ball valve on the primary drain (should've used a gate valve like everyone said).

There is also glass-holes that sells kits for all the pieces. It can also give you an idea of all the pieces you would need.

With this setup I don't have to worry about the sump overflowing from back siphon as the return is high enough and the sump is big enough to handle the water. I also don't have to worry about the siphon restarting on the overflow like with a HOB. I made the return section of the sump small enough that even if the overflow got clogged somehow, the return would run dry before overflowing the tank.

This is almost exactly what I plan to do. I originally was planning on the glass-holes overflow but that only has one drain, and the eshopps eclipse has two so I'm leaning towards that.

Can I see pics of your setup?

I'm not completely sure what I want to do as far as the plumbing goes. I'm thinking rigid PVC throughout, and lots of unions, in case I want to change something in the future which is bound to happen. I'm still not entirely sure where to put the gate valve (or ball valve) or if I'd need more than one.

 

[roberthu526]

I believe if you have the option to drill the tank you will be kicking yourself later if you don't. HOB overflows have a far higher chance of failure and just don't look as good.

I also have a 30 gallon with a 20l DIY sump. I used an eclipse small internal overflow that comes with a holesaw and template. I used a 1/2 inch return (3/4 would've been fine). For the return I just pieced together what I needed on BRS. They list and sell the holesaw you need for whichever bulkhead you get. My return pump is a sicce syncra 1.5 (357gph).

For the plumbing I used pvc from the return and overflow and had it switch to soft line under the stand. I have a ball valve on the primary drain (should've used a gate valve like everyone said).

There is also glass-holes that sells kits for all the pieces. It can also give you an idea of all the pieces you would need.

With this setup I don't have to worry about the sump overflowing from back siphon as the return is high enough and the sump is big enough to handle the water. I also don't have to worry about the siphon restarting on the overflow like with a HOB. I made the return section of the sump small enough that even if the overflow got clogged somehow, the return would run dry before overflowing the tank.

First of all let me say that I have had three eshopps HOB overflow for a total of three years and I have not had one failure yet. However I am kicking myself for not drilling it when I had the chance. Not because of higher risk but due to the fact that I am not able to fully cover the top. The U tube is a pain in the butt to deal with when you have wrasse and goby. I have a total of five glasses and acrylics on the top to make sure there is no gap for the fish to jump out. It is so painful to maintain that I am actually going to take down one of my 125G to drill on the back. I really want a clean look not just in the tank but also around the tank. A HOB just doesn't get it done.

 

[AdamNC]

I too have been debating on whether to drill or just get a hob overflow. After reading one too many articles and posts on multiple forums. I came to the conclusion to buy a new tank and drill. Have you looked into a Bean Animal overflow? It looks complicated at first but after studying it a bit you'll see it's the most fail safe set up.

 

[samnaz]

I too have been debating on whether to drill or just get a hob overflow. After reading one too many articles and posts on multiple forums. I came to the conclusion to buy a new tank and drill. Have you looked into a Bean Animal overflow? It looks complicated at first but after studying it a bit you'll see it's the most fail safe set up.

I have since decided I will be drilling my tank, for sure. I feel like I made this thread ages ago, geez. I have read, and read more until my eyes bled (felt like it anyway).

I'm not afraid to drill. I am confident that have prepared enough, so much in fact I imagine it will be a piece of cake.

Plumbing on the other hand, wassn't as simple and straight forward. Once I fully understood the Herbie style overflow, I chose to go with that because it seemed the most practical for a small 30 gallon tank. Mostly thanks to gmacreef.com and this article in particular: http://gmacreef.com/herbie-overflow-reef-tank-plumbing-method-basics/

I purchased the Eshopps Eclipse S overflow box and had planned on drilling and installing this week. It occurred to me that I hadn't even considered a Bean overflow yet, and I should before I start drilling holes and all. Turns out it's not all that complicated, and totally doable for a 30 gallon tank. Not to mention it allows for more flow through the return to feed a manifold and reactors if I decide I want them in the future, and it doesn't require constant fine tuning if flow varies.

I returned the Eclipse S overflow today. I am now trying to decide on either the Eclipse L, or a Modular Marine 1200. The overflow box must be 14 inches long or less, so that doesn't leave many options.

 

[Even Further]

You're on the right track. Drilling it now is the smart route.

I'm doing a Herbie on my 37 gallon. I used a modular marine internal box, and an external box made of glass, siliconed to the tank. I have no bulkhead between the tank and external box. MM makes nice products.