Bulkhead Fitting

[Strength&Honor]

Well this will be my first attempt at any type of bulkhead use and am looking for some of you guys with drilled tanks input on what size you would reccomend.

I was going to do a 75 in which I was going to just two 1 inch bulk heads in the overflow (I am thinking of using both bulkheads as overflows to the sump, no return from overflow for better flood protection) but on the 90 I think I should get a larger amount to the sump (with larger pvc) to bump up the return flow rate from the mag.

Anyway would you guys suggest using two 1 1/4 (this is what I am leaning towards right now) inch bulkheads or two 1 1/2 inch (I feel this is too much) bulkheads? I dont know the flow rates of the different pvc sizes so thats why I am really asking (anyone have info on the flow rate?) I was going to use either a mag 9.5 or mag 12 for return but dont know what sized pipe would be capable of handling the flow without running the pipes to the max... any help would be much appreciated

I was going to use my return for flow purposes but decided agaisnt it for saftey reasons and instead will use sump return as additional flow ontop of either powerheads or a closed loop system (contemplating the closed loop...)

 

[twilliard]

Well I have a 1 1/4" to the sump and a 3/4" return on a 120G
The only thing I wish I had was a 1" for my return. The 3/4" just barely cuts it.
About the mags you want to use. For a 75G tank dual 1 1/4" returns might be an overkill. I dont think a mag 12 will fill 2 1/14" returns due to the fact that you will have head length (if thats what its called-the length of your return). Now maybe a bigol Iwaki pump would

 

[Strength&Honor]

O my bad I sorda confused this for ya guys. Its going to be a 90 gallon tank and the return mag 12 is not set in stone yet (I could upgrade to a mag 18 which would give me 1375gph at 4.5 ft of head) but everyone has been saying not to go overboard on flow through the sump (because this will cause lack of preformance of the skimmer and could cause drainage problems.

also Ill have ball valves to help control the flow on the overflow. But you dont think a mag 12 would work? (return lines will be 1 inch going to either side of the tank, not through the overflow)

 

[twilliard]

Im no expert on the Mags but I know that all the pumps I used before the Little Giant I had a heck of a time pumping the water back up after I shut it off. Granted it was a Rio HF pump but just didnt have the "umpfh" to get it up that pipe.

Now the little giant is different, turn it on and no worries about not pumping the water uphill

 

[mfinn]

These 2 links should help you with flow rates and what to expect out of certain pumps.
They are on the reef central home page.



http://www.reefcentral.com/calc/drain.php
http://www.reefcentral.com/calc/hlc2.php

 

[Slickdonkey]

If you can fit the larger pipe in (1.5"), I would use it. It will give you more flexibility if you want to change something down the road.

 

[pactrop]

I like to overboard on the overflows. better too big than too small.

also look into the little giant. I have a few mag drives I use for changing water but to run them all the time they are some of the most expensive energy users on the market. but they do have "umpfh".