Return line question

Pulcher

Plecostomus
MFK Member
Mar 18, 2007
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Florida
So on my new tank that i recently bought there is not a return line and i have to drill one myself. i am wondering, would it be better to drill the return line in the side of the tank or drill a hole on the top and have it come over? I do have an overflow with a weir in the tank.
 

pacu mom

Goliath Tigerfish
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Jun 8, 2006
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Does the overflow box have two holes in the bottom? If so, you can run a return pipe up through the overflow box. The return pipe can come up through the overflow box and then bend and enter a hole in the top of the tank. If plumbed this way, all the plumbing is hidden under the canopy. My tank came with a hole drilled
for the return line. The return pipe could also come from the back and over the top to that return hole.

 

Pulcher

Plecostomus
MFK Member
Mar 18, 2007
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Florida
The overflow box only has my intake drains in them so i will have to drill new holes. I drew in paint where i would like them to go on the side of the tank, i am just wondering if it would be better there or if i should run the pipe to the top of the tank. I was worried about possible siphon issues if i was to lose power.

12829F66-125F-4220-8105-713043D71B93.jpg
 

pacu mom

Goliath Tigerfish
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Jun 8, 2006
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You will have a little siphoning action to the height of the weir in a power outage. I happen to love holes in the top of my tank, but even with holes in the top of the tank, there could be siphoning until the water level is below the return nozzle. We added four holes to the top of our 300 gallon tank.

There really is no RIGHT way to plumb your tank. Your return can be on the top or the side of the tank. I have an irrational aversion to drilling the side of my tank for fear of a bulkhead fail. My big brutes have managed to break three bulkheads on the top of the tank by ramming into uptakes. Because I did not specify anything about my overflow boxes, this is what I got on my big tank:



The return lines come up through the overflow boxes and enter the tank between the weirs. I feel safe with this because if a bulkhead should break, any leakage will be contained by the overflow box. And besides, there is no room for return holes on the top of my tank. I had the tank builder put eleven holes on the top of my tank for the mechanical filtration I have planned.



Drill your return holes where you feel the most comfortable. I like your external overflow box.
 
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duanes

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Why do you believe it is necessary to drill a return line at all?
I always just suspend my return lines over the rim so I get lots of surface agitation to aid in gas exchange, and only drill for overflow lines to the sump.
This allows allows for changing things around if needed.

 

DN328

Potamotrygon
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Aug 14, 2014
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Fish Tank
The overflow box only has my intake drains in them so i will have to drill new holes. I drew in paint where i would like them to go on the side of the tank, i am just wondering if it would be better there or if i should run the pipe to the top of the tank. I was worried about possible siphon issues if i was to lose power.

View attachment 1293687
Funtionally I think through side or over top won't make a difference. Either way if you use loc-lines surface return agitatiion can be done. You'll have some back siphon either way.

Aesthetically, I prefer how you have it in your mock up picture and looks cleaner.
 
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