drilling tanks

[sharkbait33]

Ok, so I'm assuming drilling holes in the bottom of the tank and having an internal overflow is a lot easier and possibly more quiet then having an external overflow. I'm not quite sure on all the mechanics of the sump and overflow, but I would love to learn more about each. I guess I'm questioning the set up of it all. I have a 180 gal tank and a 55 gal sump. My tank isn't drilled, but I would prefer an internal overflow. So to my knowledge, I would need to drill 2 holes, either in the center or a corner that'll have 2 pcp pipes running from the sump up into the tank and "spit" out over/right on the top of the overflow box into my tank. Is that correct so far? And this produces better filtration and water movement? How many inches should the holes be and where would I go about buying an internal overflow box?

Any advice helps! I'm a newbie Thanks for looking!

[4R00P3R]

most tanks cannot be drilled through the bottom because it's made of tempered glass. if it's not tempered you will need to build an internal overflow box or use sloted PVC that goes all the way to the surface of the water. fish proteins and oils rise to the top of the water and that's why overflow boxes are used. they skim the dirty water from the surface.

I'm not sure what you mean by "'spit' out over/right on the top of the overflow box into my tank". the pvc stays within the overflow box, and the return pipe doesn't go inside the overflow box. you will want your return pipe and overflow pipe on opposite sides of the tank if possible. to calculate the size of the holes, you need to know the size of the pvc fittings. you find out the size of the pvc by...oh my physics class isn't going well...calculating the force of gravity on the water minus the force of friction due to the pipe. then based on force you can get velocity. after you know velocity you can calculate how many GPH your return pump provides and use the same GPH(velocity) as the amount that goes in the overflow.

Edited December 1, 2007 by 4R00P3R

[sharkbait33]

most tanks cannot be drilled through the bottom because it's made of tempered glass. if it's not tempered you will need to build an internal overflow box or use sloted PVC that goes all the way to the surface of the water. fish proteins and oils rise to the top of the water and that's why overflow boxes are used. they skim the dirty water from the surface.

I'm not sure what you mean by "'spit' out over/right on the top of the overflow box into my tank". the pvc stays within the overflow box, and the return pipe doesn't go inside the overflow box. you will want your return pipe and overflow pipe on opposite sides of the tank if possible. to calculate the size of the holes, you need to know the size of the pvc fittings. you find out the size of the pvc by...oh my physics class isn't going well...calculating the force of gravity on the water minus the force of friction due to the pipe. then based on force you can get velocity. after you know velocity you can calculate how many GPH your return pump provides and use the same GPH(velocity) as the amount that goes in the overflow.

So if my aquarium is tempered glass I'll have to result to an external overflow box? And this means I won't need a sump?

[semperfimarine1]

if the glass is tempered it means you can NOT drill in it cause itll crack and be useless. meaning youll have to get a external overflow and yes you will need a sump

[4R00P3R]

Another way, that I should have thought of earlier, to measure the necessary PVC size is to find out what the return pump recommends. then use at least the same size or preferably one size larger PVC for the overflow.

[sharkbait33]

So the PVC pipes are attached to an external overflow that lead into the sump? What size overflow would suffice for an 180gal tank?

Sorry guys, I'm pretty new to this all! I'm extremely excited to get this tank up and running though! Thank you for everyone's help!

[4R00P3R]

So the PVC pipes are attached to an external overflow that lead into the sump? What size overflow would suffice for an 180gal tank?

Sorry guys, I'm pretty new to this all! I'm extremely excited to get this tank up and running though! Thank you for everyone's help!

That depends on the size of the sump and the velocity of your return pump. Like I was trying to say, the pump will say a size of pipe needed. You should use a pipe at least that large, but preferably one or two sizes larger for the overflow.

Edited December 3, 2007 by 4R00P3R

[sharkbait33]

That depends on the size of the sump and the velocity of your return pump. Like I was trying to say, the pump will say a size of pipe needed. You should use a pipe at least that large, but preferably one or two sizes larger for the overflow.

Is there a certain brand of pump you would recommend?

[Wryknow]

Just FYI - be careful with hang-on type over flows. If you have a power outage bad things can happen because the overflow can lose siphon. when the power comes back on the return pump will flood the tank. I highly recommend using a drilled tank for a reef aquarium.

[4R00P3R]

Just FYI - be careful with hang-on type over flows. If you have a power outage bad things can happen because the overflow can lose siphon. when the power comes back on the return pump will flood the tank. I highly recommend using a drilled tank for a reef aquarium.

They will only loose siphon if your hose is lower than the U pipe. I wouldn't worry about that. I use a hang on and never had a problem when my power went out. We all prefer drilled tanks, but cost and practicallity prevail. I recommend the eheim, or mag drive pumps. There is a poll thread in the other section addressing this exact debate. You will find more info than I can give you there.

[sharkbait33]

They will only loose siphon if your hose is lower than the U pipe. I wouldn't worry about that. I use a hang on and never had a problem when my power went out. We all prefer drilled tanks, but cost and practicallity prevail. I recommend the eheim, or mag drive pumps. There is a poll thread in the other section addressing this exact debate. You will find more info than I can give you there.

So when searching for an overflow box, how do I know which size to get? Are they like protein skimmers, in which they're rated for "up to so many gal?" Thanks for your help!

[bananags]

-drill the back unless you are 100% sure it's not tempered glass on the bottom, most if not all Oceanic tank has tempered bottom (non-reef ready tank)

-drain should be 1.5" each (maybe you can get by with 1" holes , maybe not, too small) (personally, i use one 1.5" on 125 gal)

1 drain hole, 2 holes,... your choice, just need at least 1 hole ;-) , i am sure you need a fast pump to circulate the 180gal, so it does not matter, if drain is both side or one, they all goes into the drain.

-you can buy overflow box for $$$ (about $99 for one over flow), or make your own.

or just use a pipe up and screen like at the many fish store setup (90deg pipe to the back wall and run up to maybe 1" from surface water), you don't really need an overflow box to have surface skimming.

if you do this right, there is no more risk involve than using the internal overflow box

180gal, you really need to take your time to plan and test. drill is the only way to go for tank of this size

good luck.

Ok, so I'm assuming drilling holes in the bottom of the tank and having an internal overflow is a lot easier and possibly more quiet then having an external overflow. I'm not quite sure on all the mechanics of the sump and overflow, but I would love to learn more about each. I guess I'm questioning the set up of it all. I have a 180 gal tank and a 55 gal sump. My tank isn't drilled, but I would prefer an internal overflow. So to my knowledge, I would need to drill 2 holes, either in the center or a corner that'll have 2 pcp pipes running from the sump up into the tank and "spit" out over/right on the top of the overflow box into my tank. Is that correct so far? And this produces better filtration and water movement? How many inches should the holes be and where would I go about buying an internal overflow box?

Any advice helps! I'm a newbie Thanks for looking!

Edited December 4, 2007 by bananags

[4R00P3R]

I would not drill the tank. If you have an Oceanic, the resale value is pretty good, but not if you drill it. I recommend a standard overflow box. Usually they are rated with "up to ___ gph". If you have a 180 with a 55g sump you will most likely want a Mag-Drive 9.5 or an Eheim 1262. You could even use one as large as a Mag18. These should provide about 750gph of flow (or 1200gph for the 18) so you need an overflow box that's rated accordingly. I use a Mag12 and I only have a single overflow, but it just barely keeps up with the pump (possibly bad pump or under-rated overflow).