My 315G Plywood Tank Build

[David K. Bradley]

Yeah, I'll bet she does!

Seriously, she wanted to convey her thanks as she's been trying to get me to larger, but does she really know what's involved with building one of these things? I'm not sure she truly understands the concept of what it takes to build an effective and really nice looking one for a house. But a 12 ft.'r. Man-oh-man. I might as well build one between the walls of my tank room when it gets done, instead of just a 8' or 10' long one and about 8' front to back, instead of 4'. Crap, what's the volume of that one? 4'x8'x12'=663552.00/231=2,872.519481 U.S. GAL. . . . . OMG!
Another monumental build. What size of viewing window and how thick do I use on this one? 1" thick X 36" high 10' long? Or should I get 2- 5 ft.'rs and a 6"x 6" post in the cntr.? I owe you, Ross.

 

[BadOleRoss]

I am going to be changing my filtration! Right now I have 2-1.5" bulkheads that are overflowing into my sump. I am only getting about 950 gph through the tank itself which is only 3 turns per hour. I am going to remove the bulkheads and add 2 overflow boxes to the back of the tank. I will accomplish this by cutting out openings in the top back area of the tank, attaching the boxes, and sealing them with liquid rubber. I will have 2-1.5 bulkheads going out the bottom of each box. This will more than double my current flow. I am going to place poret foam in the boxes to act as a prefilter and keep the fishes out. Of course, I will take pictures. Going to start working on the boxes Wednesday.

 

[David K. Bradley]

Looking forward on the progress of your over flow boxes as never used a sump filtration or overflow boxes before, this should be interesting to see and read about. Good luck on your progress.

 

[the_deeb]

External overflows are really nice if you have the room behind the tank. I'm not sure it's a good idea to prefilter your overflows with foam, specially considering you're trying to maximize your flow. I used to have an HOB overflow box that had a small foam prefilter and it used to clog up very quickly. This used to reduce the flow enough that my overflow couldn't keep up with my return pump and almost overfilled my tank a few times. If you want to prefilter your overflows to prevent fish from getting in there I think it's safer to just use netting or coarse mesh that doesn't run the risk of clogging, and then having your first foam layer in the sump where it's easier to include bypass safeguards to deal with potential clogs.

Is there a reason you want to add overflow boxes rather than just adding two more 1.5" bulkheads to your current setup? Seems like that would be easier and would give you similar flow. Alternatively you could just expand the size of your current bulkheads to 2", which would almost double your flow.

 

[john73738]

I am going to be changing my filtration! Right now I have 2-1.5" bulkheads that are overflowing into my sump. I am only getting about 950 gph through the tank itself which is only 3 turns per hour. I am going to remove the bulkheads and add 2 overflow boxes to the back of the tank. I will accomplish this by cutting out openings in the top back area of the tank, attaching the boxes, and sealing them with liquid rubber. I will have 2-1.5 bulkheads going out the bottom of each box. This will more than double my current flow. I am going to place poret foam in the boxes to act as a prefilter and keep the fishes out. Of course, I will take pictures. Going to start working on the boxes Wednesday.

Ross, I have to agree with the_deeb, if you are going to prefilter to keep from loss of fish them make the foam as course as possible, I put a sponge filter on my pump feeding the filter and it nearly cut the flow in half, and that was a new filter. I would just protect the fish with egg crate or something. you defiantly have enough media in your sump so prefiltering does not seem all that necessary.

 

[BadOleRoss]

External overflows are really nice if you have the room behind the tank. I'm not sure it's a good idea to prefilter your overflows with foam, specially considering you're trying to maximize your flow. I used to have an HOB overflow box that had a small foam prefilter and it used to clog up very quickly. This used to reduce the flow enough that my overflow couldn't keep up with my return pump and almost overfilled my tank a few times. If you want to prefilter your overflows to prevent fish from getting in there I think it's safer to just use netting or coarse mesh that doesn't run the risk of clogging, and then having your first foam layer in the sump where it's easier to include bypass safeguards to deal with potential clogs.

Is there a reason you want to add overflow boxes rather than just adding two more 1.5" bulkheads to your current setup? Seems like that would be easier and would give you similar flow. Alternatively you could just expand the size of your current bulkheads to 2", which would almost double your flow.

Right now my bulkhead are mounted on the back wall of the tank which is OK for flow but not great. I think if I mount the bulkheads in the bottom of the overflow boxes I will get better flow. As far as just adding 2 more bulkheads, it would be a tight fit to get another bulkhead on either side of the existing BHs, I centered the BH within the space that it was designed to go. As far as the foam, I am going to be using Poret 30ppi foam. I have this in my sump already and I will be cleaning it off every day or so. I will be watchful for overflows.

 

[BadOleRoss]

Ross, I have to agree with the_deeb, if you are going to prefilter to keep from loss of fish them make the foam as course as possible, I put a sponge filter on my pump feeding the filter and it nearly cut the flow in half, and that was a new filter. I would just protect the fish with egg crate or something. you defiantly have enough media in your sump so prefiltering does not seem all that necessary.

I have some egg crate here and screening material as well just in case I am not happy with the foam or its a total fail. Poret foam is a very corse foam and does little or nothing to slow down water flow. I have 10, 20 and 30ppi in my sump and the water goes through just fine. I will post some pics/video when I get it going.

 

[the_deeb]

Just keep in mind that in your sump the water flow is being spread over a fairly large area of foam, whereas in an overflow prefilter it's going to be restricted to a much smaller area, which will increase the rate at which it gunks up. That being said, I was just using regular old Big Al's foam, not the fancy Poret stuff. If you're cleaning it everyday (which I wasn't) you'll probably be fine.

Any updated pictures of the tank? Has the pond coat started to turn brown yet? I was hoping for a black background on my tank which is one of the factors that has prevented me from committing to using pond coat on my build so far.

 

[BadOleRoss]

I did some work on the overflows tonight but didn't take any pictures. I will try to get some up in the next day or so. I am thinking about installing the new overflows on Wednesday. The PC has browned up nicely. I hesitate adding the new overflows becuase they are going to look different for a month or so until everything evens up.

 

[BadOleRoss]

Okay, I removed my old bulkhead fitting today on my tank and installed my DIT overflow boxes. I am going to try to post some pictures doing it old school so we'll see how it turns out.
This is a picture of the screen bulkhead that I am removing. There are 2 of them and I am just not getting enough water flow to the sump using these and I dont have the room on either side to add 2 more.

After removing the bulkhead, I cut out the area between the bracing to allow a space for the new overflow boxes.

Here is what the new box looks like. It's made of plywood and coated in liquid rubber. There are 2 1.5" bulkheads going out the bottom of each box into a 3" pipe that leads to the sump. A 3" pipe will enter each end of the sump.

Here is the box, well one of the boxes installed with a fresh coat of liquid rubber. I will be putting poret foam in the front of the box to prevent fish from entering it. The main body of the box will be opened for right now but it will be a nice place to put filter media in the future.