need help: where to drill & overflow size

[cmantis]

I could use some help. I have 40g breeder tanks (36"l x 18"w x 17"h). I will be using 2x 1" bulkheads for drain (beananimal/herbie) and 2x 1/2" returns. I will have two of these tanks plumbed to one 30g long sump/refug. Right now I have a Rio+ 3100 (900gph) pump but could get bigger if needed.

How far down and from the sides should I drill the drains and returns? I have looked all over but can't seem to find directions on where to place the holes.

What size overflow box should I have built? I have someone custom making them for me.

Thanks!

 

[Entropy]

From my experience all the holes should be drilled at the surface of the water (however high or low you decide you want that). I would go at least two inches from the corner. I would put the overflow/drain in the middle, but that is just personal preference. Also I would go with 3/4" returns. You can always reduce them down for whatever reason, but it is hard to make the holes bigger later.

 

[cmantis]

From my experience all the holes should be drilled at the surface of the water (however high or low you decide you want that). I would go at least two inches from the corner. I would put the overflow/drain in the middle, but that is just personal preference. Also I would go with 3/4" returns. You can always reduce them down for whatever reason, but it is hard to make the holes bigger later.

I already ordered all the stuff for 1/2" is that bad? I will have two of them on each tank though.

 

[Entropy]

Nothing wrong with 1/2". I just like to go bigger since you can always downsize a bulkhead.

 

[cmantis]

So what dimensions overflow box should I have made?

 

[cmantis]

So now I am thinking using a weir inside and external to save some space. Using 2x 1" drains on a 40g breeder (36x18x17) what sizes should I make each. Looks like I am going to have to go to a glass shop and try to make these myself. Are both just 4 sided boxes or does the front of the weir have to be shorter or angled for skimming? Also for the holes in the tank between the two boxes should they be 2x 1" or 2x 1/2" (those are my two saw sizes - and how many holes can each saw cut before it is no good). If anyone wants to help make these for me that would be great as this is my first time and I am pressed for time. Thanks in advance.

 

[Donkeykong]

You say you are using a 1" bulkhead but only have a 1" hole saw , a 1" inch bulkhead needs a 1 3/4" hole to work. You might want to look into glass holes .com, they have some really nice kits that include everything you need like the overflow box, bulkhead, appropriately sized hole saw, template for position of holes.

 

[ktg113]

I drilled my holes the width of the bulk head from the top and sides/ next to each other. So I had a 1 in bulk head so there was a space of a 1in all around the side of the hole

 

[cmantis]

Do you think 2x 1/2" returns will be enough or would 3/4 have been better? I already got everything I need for 1/2 returns but want to make sure before I drill.

 

[ktg113]

I would say the 3/4 would be better because you could always reduce to 1/2 but you are running a 40 breeder i would say 1/2 inch would be fine. I have (2) 3/4 returns on my 180 so I would say you will be fine with 1/2.