Big Tank, Big Questions (overflow box and return)...

[terd ferguson]

I finally got my tank put back together from when my neighbor dropped it carrying it in the house. Assuming there are no water leaks, I'll get started on the stand in a couple of days. I have some questions regarding the overflow box and the return line.

First, the overflow box. The tank is drilled with 3 holes (2 for drain and 1 for return) in the center. The overflow box was mounted in the center of the tank (the very middle, 'center overflow' style). I don't like this at all because I feel it takes away from viewing and is distracting. I want to move it to the center of the back wall.

I've made a drawing kind of representing what I want to do. Do you guys forsee any problems with doing it like the drawing? Will I need to worry about the drain pipes moving around? Check out the drawing below (top is before, bottom is how I want to do it)...

Now, on to the return line. Like I said above, the tank is drilled with 3 holes in the bottom. How should I run the return line. I guess the two options I'm considering are: 1. Run it into the overflow box like the 'after' picture in the drawing, and then up and over the box back into the tank (more head loss this way, but easier). Or, 2. Construct an undergravel jet type setup (less head loss but more complicated).

So with regards to the return line, what would you do and why would you do it that way and how would you go about doing it?

I'm open to any and all suggestions and/or comments. Thanks very much in advance for the help. And thanks for this great forum.

 

[terd ferguson]

Bonus shot of the tank back in one piece...

Tank measures 60" long x 24" wide x 30" tall. The broken piece was one of the 60"x30" pieces and can be seen up against the wall over to the right. The tank will be filtered with a wet/dry sump. The sump is ready to go, I'm just waiting for these small details with the tank to be worked out and to build my stand.

Once again, any and all help is greatly appreciated. Thanks very much.

 

[pacu mom]

I finally got my tank put back together from when my neighbor dropped it carrying it in the house. Assuming there are no water leaks, I'll get started on the stand in a couple of days. I have some questions regarding the overflow box and the return line.

First, the overflow box. The tank is drilled with 3 holes (2 for drain and 1 for return) in the center. The overflow box was mounted in the center of the tank (the very middle, 'center overflow' style). I don't like this at all because I feel it takes away from viewing and is distracting. I want to move it to the center of the back wall.

I've made a drawing kind of representing what I want to do. Do you guys forsee any problems with doing it like the drawing? Will I need to worry about the drain pipes moving around? Check out the drawing below (top is before, bottom is how I want to do it)...

Now, on to the return line. Like I said above, the tank is drilled with 3 holes in the bottom. How should I run the return line. I guess the two options I'm considering are: 1. Run it into the overflow box like the 'after' picture in the drawing, and then up and over the box back into the tank (more head loss this way, but easier). Or, 2. Construct an undergravel jet type setup (less head loss but more complicated).

So with regards to the return line, what would you do and why would you do it that way and how would you go about doing it?

I'm open to any and all suggestions and/or comments. Thanks very much in advance for the help. And thanks for this great forum.

Our return pipe comes up through the overflow box, two right-angle bends and then re-enters the tank. We have a big spray nozzle on the end that really helps to aerate the tank. In the following picture, the pipe comes out of the overflow box and enters the tank again through the black bulkhead on the far right (the black hole).

This tank on ebay shows it more clearly:

http://cgi.ebay.com/NEW-180-GALLON-...ameZWDVWQQrdZ1QQcmdZViewItem#ebayphotohosting

 

[terd ferguson]

Our return pipe comes up through the overflow box, two right-angle bends and then re-enters the tank. We have a big spray nozzle on the end that really helps to aerate the tank. In the following picture, the pipe comes out of the overflow box and enters the tank again through the black bulkhead on the far right (the black hole).

This tank on ebay shows it more clearly:

http://cgi.ebay.com/NEW-180-GALLON-...ameZWDVWQQrdZ1QQcmdZViewItem#ebayphotohosting

Thanks, that helps a lot. How deep into the the tank does the return line extend?

Thanks again for the help.

 

[pacu mom]

Thanks, that helps a lot. How deep into the the tank does the return line extend?

Thanks again for the help.

The spray nozzle is just a few inches below the waterline.

The return line is from our mechanical filtration system--2 spa filters run with a big hammerhead pump (5800 gph) This system creates a very swift current in the tank, which the fish all love. The tank is well aerated as this pic taken with a slow camera shows:

Here's a video clip taken at the end of a water change when we rapidly pump in the last 100 gallons of water. Our fish love to play in the rough stuff.



The beauty of overflow boxes is that all the pipes can be hidden under the canopy....in our case, behind the light fixture.

This is what our tank looks like behind the light fixture:

The pipe on the far left front is the mechanical return coming up through the overflow box. The pipes on the right and in the back are mechanical uptakes--our poop suckers. The ugly hose is the return from the FX5/UV sterilizer. Further on down and not in view are the FX5 uptake hose and at the extreme end of the tank is the main mechanical uptake pumped into the hole next to the 2nd overflow box. It comes down about the top 1/3 of the tank

We were newbies when we set up our system. We capped off the second overflow box (bulkheads with capped off pipes). The overflow box is full of water and has the 300 W thermometer in it. The spray return from our large wet/dry filter (3/4" hose with the spray nozzle on the end) hangs in this full overflow box.

The overflow box in use has a bulkhead with a pipe running to the wet/dry filter, and a bulkhead fitting with a pipe returning from the mechanical filters and a pipe extending up through the overflow box and then entering through the top of the tank.

I guess what I'm trying to say, is that there is no one RIGHT way of doing anything. Most people would have plumbed both overflow boxes to their wet/dry filter...we didn't, and we have great water parameters.

 

[terd ferguson]

Thanks a lot for the pictures and ideas. I guess I'll just plumb the return line through the overflow box and then up and over and back into the tank.

I'm still looking for any suggestions as to whether or not I should be worried about the pipes moving in the relocated overflow box (as in the 'after' drawing).

With the original center overflow design, the pipes went straight down into the bulkheads. When moving the overflow box to the rear of the tank, the pipes will be kind of free standing inside the overflow box with no support, except for the very bottom where they come into the overflow box (see above 'after' drawing). Will this present any problems?

 

[pacu mom]

Sorry, but I didn't read your first post carefully enough...I thought the drain pipes were under the tank. With bulkheads in the holes, the pipes would be fairly rigid. Is drilling three new holes under the relocated overflow box an option? If so, the original three holes could easily be capped off by using bulkheads. Either way should work for you.

 

[terd ferguson]

Sorry, but I didn't read your first post carefully enough...I thought the drain pipes were under the tank. With bulkheads in the holes, the pipes would be fairly rigid. Is drilling three new holes under the relocated overflow box an option? If so, the original three holes could easily be capped off by using bulkheads. Either way should work for you.

I'm afraid drilling more holes on the bottom at the back isn't an option. Besides the 1/2" thick glass, there are two braces (one in front and one in back) underneath the tank exactly where the holes would have to be drilled.

 

[terd ferguson]

Another question has come to mind. When moving the overflow box to the rear in the center, how should I account for the silicone seal on the tank floor. With the seal there, the box doesn't sit all the way flush up against the glass.

Really only one solution comes to mind immediately. That would be to cut a small notch in the bottom rear of the overflow box to account for the extra silicone in the tank bottom and then silicone around this notch, sealing any small spaces created by the notch.

Wow, that's kind of hard to understand. If you guys have any other suggestions for me, I'd be glad to hear them. Thanks again.

 

[Danh]

Wow... I didn't realize you're moving the box... Why???? If it were me, I would use that kind of overflow with a double sided tank and use it as a center piece in the room. Like right where you've got it sitting. Viewable completely from all sides.

You are goin to drill holes in the side of the box at the bottom, right? It looks like it's going to be really hard to get a good seal on that pvc L piece that is inside the tank. Then you'll also have to make sure everything is good and sealed inside the box, which isn't easy to do either. It just seems like a better idea to deal with it in the center.