bulkhead fittings

[dean9922]

Hi Everyone....I have made 2 plywood tanks, 100 gallon and 76 gallon. I have been doing manual water changes with 5 gallon pails and it is getting to be a real pain in the ass.

My question is, what is the best size diameter bulkhead to use on these tanks (3/4" plywood tanks) as drilling them is not a problem. Also how far down from the top do you drill them. I know you don't want to do it at the bottom of the tank. I currently am running aquaclear 110 filters on both along with hydro sponge filters. I would like to maybe get into an easier water changing system.

I would plumb in the 2 bulkheads (one on each tank) with a manual valve to turn on when I want to drain the water. This will be gravity fed to floor drain which is about 20 feet from tanks. Then use a external pump from the two 55 gallon holding barrels back into the appropriate tank. It seems this would be a lot less work then hauling 5 gallon pails. The pictures of the tanks are what I'm dealing with and the plumbing pipes would probably mount on the left side of one tank and right side on the other tanks for ease of opening the valves.

also, on the inside of the bulkhead can you attach a gravel cleaner as the tank is draining to clean the debris etc.....

If anyone has any ideas, that would be great.

 

[dean9922]

anyone??????

 

[nfored]

I Drill my tank at the top, and then have a 90 elbow with a pipe extending down; to the level I wish to drain to. This way if there is a bulkhead failure then I lose almost no water, but I can still drain to the level I need. While this is not as fast as a bulkhead drilled at the level I want to have the water drained to, it does work and is safer.

I run the return line above the water level to prevent back siphon.

Edit: Nice tanks.

 

[Pharaoh]

I typically like to drill towards the top of the tank.

 

[Nutish]

connect one end a pipe to the outlet of ur pump and the the otherend to the outside and switch it on!!!

 

[dean9922]

thanks for the responses. However if you drill the bulkhead near the top of tank, are you talking 1/3rd of the way down the tank. I want this to be gravity fed and use the external pump to pump back into the tank from the holding tanks.
Also how big of bulkhead would be adequate....is 3/4 diameter to much or should I just use 1/2 inch....thanks again

 

[JAFRIAS]

3/4'' is fine , placing a elbow along with pvc pipe into the tank coming from the bulkhead then drilling a small hole into the pipe where u would like the water to stop ''1/3 way'' just might work