Wasn't quite sure how to word the title so I put in what my question pertains to. So I have a nano, and I will be drilling the tank to put in a herbie over flow. I was planning to use 1" pipes, but in my rimless nano (17 gallon, same size as 60p), having 2 1" pipe elbows in the tank seems a bit intrusive (but I would learn to deal with it if I have no other choice). I try explain, but I will attach a rough drawing of what I mean. So I was thinking of making/ finding a small glass box, and drill 2 holes at the bottom for the inlets, at 1" each. I was going to also drill a 2" hole on the side to connect it to a drilled 2 inch hole on the tank. They would be connected through a bulk head, and I would silicone the external box onto the tank (but if I don't have to I won't). Will this work? should I change anything? Thanks
Would this work? Overflow box, pipe size, herbie, external
- Thread starter jfishy
- Start date
uncleof6
Active member
Box is too small, and the holes will be too close together. Quite honestly, you are wasting your time putting in a siphon system for a 17 gallon tank? Use an HOB overflow, with a 1.25" or 1.5" durso type drain system and call it a day. You are not going to have enough flow (reasonably <= 170gph) to justify using a 1" siphon system, and smaller pipe diameters plug up too easily. You really can't justify a siphon system for < 350 gph. (Problem zone for a 1.5" durso.)
pmrossetti
Active member
totally agree.
gaberosenfield
New member
It will work. Many people do external overflow boxes. You don't need a bulkhead to connect the overflow box to the tank. Just silicone it. In fact, you don't even need a complete overflow box. You can make an overflow box missing one side and just silicone the edges of the open side onto your tank. Look up external overflow boxes and you'll see some great examples of this.
uncleof6
Active member
Lots of things work, and 'work' is a very ambiguous recommendation. The thing is to justify the method you want to use. For a tiny tank like this, there is no justification for going to such lengths. Also, in this case how is the water going to move from inside the tank, to the outside, unless you have holes in the back of the tank, and if there is no internal weir, the whole thing will be useless anyway...the drawing does not show anything inside the tank...just through bulkheads. So in this case 'work' means it will drain water, but it will not do anything required of an overflow, and therefore is not an overflow...
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dmh8801
New member
Not true. If the return area in the sump is sized right you will only have a limited amount of water for the return pump to push back into the display.
kegogut
Active member
Thats true but it will still break siphon causing your pump to run dry which is a problems by itself.
dmh8801
New member
True, if it would loose siphon the return area would run dry. But no flood as long as your return section was setup correctly.
That leads to another question. How would it loose siphon? The only ways for it to loose siphon would be; part failure, not setup correctly, or improper flow (like using a box with two U tubes when you only have enough flow to support one).
kegogut
Active member
It would lose siphon by building up air in the U-tube. little bit at a time until it eventually has enough air in there to break siphon. Of course there are ways to get by that,but I wanted the OP to know about the hazards that can occur by using a HOB overflow.
I recently had my mantis tank break siphon and put about 20 gallons on my floor. It allowed me to talk the wife into letting me upgrade his tank from a 40 non-drilled to a 58 drilled so it was totally bad but its never fun to have water on the floor.
I recently had my mantis tank break siphon and put about 20 gallons on my floor. It allowed me to talk the wife into letting me upgrade his tank from a 40 non-drilled to a 58 drilled so it was totally bad but its never fun to have water on the floor.
