Overflow hole requirement for 75 gallon tank

aiq25

New member
Hello. Originally I was going to use a PVC overflow but I think I will try to drill some holes into my tank now, since I'm changing tanks. I was wondering what size hole would be required for a 75 gallon tank?

Also, there is any tutorial someone can point that covers DIY overflow box and plumping? I'm not exactly sure what is needed for the return water line from the sump to the display tank.

Thank You.
 

a6walter1

New member
I drilled my own 75 Gallon tank last spring. I ended up using a single overflow box in the middle with 2-1"drains inside. I cant remember what style it is, but one drain is in full siphon while the other is for emergencies. The main drain goes into a filter sock, while the emergency just goes right into the sump. As for return plumbing, I have a mag 7 plumbed with 3/4" pipe up to the top of the tank, then it T's off into 2 1/2" lines returning to either side of the tank. They are finished off with some loc-line and flared nozzles.
 

zachts

New member
Hmmmm. How exactly would I go about doing that. Do I make all 4 holes the same size?

Sorry if I'm kinda hijacking the thread. Not my intentions.

Just extend the holes up to the water level with riser pipes from the bulkhead. If they are not all the same size you'd use the smaller one as the siphon and the larger two as open channel and emergency. the second smaller hole would be return line. Gate valves would go under the tank.
 

SGT_York

New member
doesn't work, you cannot split the bean animal pipes between two overflows. If you have two overflows two herbies is the easiest solution.

For the OP a single coast to coast setup is very simple and easy to DIY. The BA is a near perfect system.
 

JuggZaPoppiN

New member
doesn't work, you cannot split the bean animal pipes between two overflows. If you have two overflows two herbies is the easiest solution.

For the OP a single coast to coast setup is very simple and easy to DIY. The BA is a near perfect system.

Well currently there aren't any overflows. I was going to drill 4 holes in the bottom for 2 overflows in my 125 gallon.

Should I go a different route?
 

zachts

New member
doesn't work, you cannot split the bean animal pipes between two overflows. If you have two overflows two herbies is the easiest solution.

For the OP a single coast to coast setup is very simple and easy to DIY. The BA is a near perfect system.

Why not? water level in the tank doesn't change, regardless of where you put the pipes one's going to be full siphon, one will be the open channel and the one set slightly higher will only get emergency flow.

siphon and return on one side and open channel and emergency on the other. Where else is the water going to go?
 

aiq25

New member
I know this is sort of old now but I wanted to get some opinions. I'm planning on doing the Bean Animal type overflow. For the overflow box I'm thinking the coast-to-coast style but planning on building it myself, so thinking of not putting any teeth (I'm going to use glass). To ensure no fish or snail go into the overflow I think I will put some kind of mesh on the top, which will also go on top of the overflow box. This tank is going to be a open top. What do you guys think?
 

RocketEngineer

Space is big.
I know this is sort of old now but I wanted to get some opinions. I'm planning on doing the Bean Animal type overflow. For the overflow box I'm thinking the coast-to-coast style but planning on building it myself, so thinking of not putting any teeth (I'm going to use glass). To ensure no fish or snail go into the overflow I think I will put some kind of mesh on the top, which will also go on top of the overflow box. This tank is going to be a open top. What do you guys think?

No teeth is best. Some folks place a layer of mesh or egg crate behind the lip of the overflow to stop snails and catch fish. Another option is a lid which is just above the water line. This gives you the surface skimming you are after while minimizing the gap things can go through. D2mini has the best example of this in his build thread.
 

NanoReefWanabe

New member
What if you have dual overfills with 2 holes each coming through the bottom?

Hmmmm. How exactly wouputld I go about doing that. Do I make all 4 holes the same size?

Sorry if I'm kinda hijacking the thread. Not my intentions.
You just asked if you had for holes and dual overflows now you are saying you don't have any holes? ....

Just extend the holes up to the water level with riser pipes from the bulkhead. If they are not all the same size you'd use the smaller one as the siphon and the larger two as open channel and emergency. the second smaller hole would be return line. Gate valves would go under the tank.
it doesn't really work like that. .. the water is never dead even in the tank. .. though the tank may be dead level, that is not to say the Yahoo building that tank put the bottom in level or that the overflows are in level or that they are the same height. ..

Well currently there aren't any overflows. I was going to drill 4 holes in the bottom for 2 overflows in my 125 gallon.

Should I go a different route?
you will 100% likely not able to drill the bottom of a 125... go out the back do a bean and do it right. .. the thread has everything you need to do it

Why not? water level in the tank doesn't change, regardless of where you put the pipes one's going to be full siphon, one will be the open channel and the one set slightly higher will only get emergency flow.

siphon and return on one side and open channel and emergency on the other. Where else is the water going to go?
this can only work if you rework the overflows so that they are linked as one. . You can do this with some black ABS/acrylic and notch and fit a large connecting wier between the boxes. .. then they will share the same body of water and work as designed

I know this is sort of old now but I wanted to get some opinions. I'm planning on doing the Bean Animal type overflow. For the overflow box I'm thinking the coast-to-coast style but planning on building it myself, so thinking of not putting any teeth (I'm going to use glass). To ensure no fish or snail go into the overflow I think I will put some kind of mesh on the top, which will also go on top of the overflow box. This tank is going to be a open top. What do you guys think?
good plan
 
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