Drilled tank - Drain and Return Setup question

nmadsen4

Plecostomus
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Dec 16, 2008
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phoenix
I have a 240G. Acrylic with drilled drain and returns in both of the back corners. My question is, when I hook up the drain and return piping. Do I want the rubber seal on the inside of the tank or outside? I have all the bulkheads, rubber seal, tubing and whatever else.... I just dont know which side of the bulk head the rubber should go on.

Thanks for the help.
 

Iron Cat

Feeder Fish
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Sep 7, 2015
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rubber seal goes on the inside (water side)
tighten the fitting hand-tight then about a quarter turn more with a wrench/pliers.
 

predatorkeeper87

Potamotrygon
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Sep 8, 2014
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seal ALWAYS flange side (inside tank). When I first got into sumps and all the craziness with them, I made that mistake. Talk about beating your head against a wall trying to figure out why your bulkheads are leaking...cramming yourself under your stand trying to tighten them just a biiiiit further haha.
 
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Iron Cat

Feeder Fish
MFK Member
Sep 7, 2015
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seal ALWAYS flange side (inside tank). When I first got into sumps and all the craziness with them, I made that mistake. Talk about beating your head against a wall trying to figure out why your bulkheads are leaking...cramming yourself under your stand trying to tighten them just a biiiiit further haha.
I did the exact same thing on my first drilled tank, teflon tape, glue, tightened until the fitting cracked etc....a few temper tantrums and a lfs visit later I had new fittings and the correct knowledge.
 

predatorkeeper87

Potamotrygon
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I did the exact same thing on my first drilled tank, teflon tape, glue, tightened until the fitting cracked etc....a few temper tantrums and a lfs visit later I had new fittings and the correct knowledge.
haha yup same here, except I just got fed up, took them out...and happened to sit down on mfk and there was a sump thread up and sure enough someone asked this same question haha
 
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duanes

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Isla Taboga Panama via Milwaukee
The rubber seal is normally put on the inside of the tank.
I have tanks with drill holes on both ends, and use both as drains to the sump, and have my returns hanging above the tank. This may seem redundant, and is
just a preference, but I figure if one drain gets plugged up (and has happened to me), the other takes up the slack, and the tank doesn't overflow onto the floor.
I also like returns to be above the water line to create as much surface agitation as possible to promote gas exchange.

 

nmadsen4

Plecostomus
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Dec 16, 2008
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Thanks everyone! I'm glad I wasn't the only one that had this question. Luckily I asked before hand.... Last think I want is leaky bulkheads and a massive headache.
 
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