overflow

[taznut]

i have a thread going about building a tank and sump... i am trying to decide how to do the overflow... system will be about 180g and i was planning on going with 2 1.5" drains and one 1" return... from what i have been looking at it seems this might be a little over kill on the drains... the return pump is a mag 18 (1800g/hr)... i think the overflow will be about 32 linear inches... if i go with just one 1.5" drain will that handle 1800gph??? i was thinking 2 so that it will be quiet and i was going to run one to the skimmer and one to the fuge (i know i can do this with a T)... what do you think...

 

[natclanwy]

A 1.5" drain will handle about 1200gph, but your 1" return will choke your mag 18 down to about 1100gph @ 4' of head pressure. What type of overflows are you planning on using?

 

[taznut]

Originally Posted by natclanwy
http:///forum/post/3006108
A 1.5" drain will handle about 1200gph, but your 1" return will choke your mag 18 down to about 1100gph @ 4' of head pressure. What type of overflows are you planning on using?
im not sure if this answers your question but it will be in the tank... not using the HOB type... going to drill the bottom of the tank and use bulkheads...

 

[natclanwy]

Yes it does, since you are drilling the tank you don't have to worry about maintaining a minimum flow rate through two overflows. So you can do one or two overflows it up to you, but two may be a little quieter.

 

[taznut]

Originally Posted by natclanwy
http:///forum/post/3006113
Yes it does, since you are drilling the tank you don't have to worry about maintaining a minimum flow rate through two overflows. So you can do one or two overflows it up to you, but two may be a little quieter.
i was just going to do one overflow and have two drain pipes in that one... does that work??? i will try and find that pic again of how i was going to do the standpipe...

 

[taznut]

see if this works...

 

[natclanwy]

Having two drains in one overflow will negate any benfits running two overflows will have as far as noise goes but will work fine. I am familiar with the durso standpipes they work very well.

 

[taznut]

Originally Posted by natclanwy
http:///forum/post/3006119
Having two drains in one overflow will negate any benfits running two overflows will have as far as noise goes but will work fine. I am familiar with the durso standpipes they work very well.
the reason i am asking is because i would like to go with the overflow in the back but if i use 2 drains i will have to put it in the corner due to the amount of acrylic i have for the overflow box... so what do you suggest??? im only doing one overflow bux so should i go with 1 or 2???

 

[natclanwy]

If you want to only do one overflow box make it as long as you can and go with the two drains. If nothing else the second drain will serve as a backup. Also the length of the overflow doesn't necessarily mean across the back of the tank you can shape the overflow box anyway your like the length is the total area that contact the water surface of the water. Heres and example a 2"x12" overflow will have 16 linear inches and so will a 4"x8" overflow.

 

[taznut]

Originally Posted by natclanwy
http:///forum/post/3006131
If you want to only do one overflow box make it as long as you can and go with the two drains. If nothing else the second drain will serve as a backup. Also the length of the overflow doesn't necessarily mean across the back of the tank you can shape the overflow box anyway your like the length is the total area that contact the water surface of the water. Heres and example a 2"x12" overflow will have 16 linear inches and so will a 4"x8" overflow.
ok. thank you... it is going to be 32" long (probably 9x23)

 

[natclanwy]

Actually 9"x23" will be 41" total you will have two 9" sides unless you put in a corner.

 

[taznut]

Originally Posted by natclanwy
http:///forum/post/3006140
Actually 9"x23" will be 41" total you will have two 9" sides unless you put in a corner.
will be in the corner...

has to be in the corner due to the size of the holes for the bulkheads... i only have 32" of acrylic and if i put it in the middle (with 2 sides) there wouldnt be much room between the holes...

 

[natclanwy]

Gotcha thought I had read earlier that you didn't want to put in the corners

You could do 6"x20" and still have enough room for the bulkheads if you didn't want to put in the corner.

 

[taznut]

Originally Posted by natclanwy
http:///forum/post/3006167
Gotcha thought I had read earlier that you didn't want to put in the corners

You could do 6"x20" and still have enough room for the bulkheads if you didn't want to put in the corner.
the bulkheads that i got i need a 3" hole for the 1.5" and they are 4" across so 6" wouldnt be enough room... i didnt really want to put it in the corner but i guess i will have to... it will be ok... i have clear acrylic anyhow so it will look wierd until that gets covered with coraline or xeinia...

 

[natclanwy]

Are you sure on the hole size, I just drilled holes for 1.5" bulkheads on a tank I am building for the local junior high and the hole size was 2 5/8". We are using overflows from glassholes and the overflow boxes are 6" wide and the nut for the bulkhead sits inside the overflow box.

 

[taznut]

Originally Posted by natclanwy
http:///forum/post/3007009
Are you sure on the hole size, I just drilled holes for 1.5" bulkheads on a tank I am building for the local junior high and the hole size was 2 5/8". We are using overflows from glassholes and the overflow boxes are 6" wide and the nut for the bulkhead sits inside the overflow box.
sorry, answering this a little late... i got the bulkheads at a tractor supply place my lfs recommended because they were out... im sure they are bigger than 'true' bulkheads but will work... i found something else that might work for a overflow that i think i might go with if someone doesnt say no... started new thread called "overflow II"