I messed up....

[Shaun Sweeney]

I just installed the same overflow so I think I know what you've done. That said, here is what I recommend:

Make a spacer plate (with the necessary matching holes) out of hard plastic as well as two more rubber gaskets. Your installation sequence is:
- internal overflow box
- gasket
- new spacer plate
- gasket
- tank wall
- gasket
- external overflow box
- nut

And, if you are still assembling and haven't installed a gated valve on one of the 3 drain lines, do it now or you will find you have a very noisy system. Lastly, the short, red overflow pipe is standard 3/4" PVC so you can tweak how the overflow box works my fabricating slightly different lengths. You will probably also need 2 PVC 90's to redirect the main syphon suction. Cut the 2nd 90 in order to keep the opening relatively close to the bottom of the overflow.

 

[thrasher1472]

Even if you make it sit flush it looks like it sitting too high to work properly. A little bit of evaporation and your overflow will be dry. Sadly a new tank is your best option but a bulkhead with a plug and you'll have a water tight sump

 

[cromag27 Verified Sponsor]

Probably wouldn't need to be plugged if used as a sump. the water depth may not even get close to the hole.

 

[thrasher1472]

True but with return pump off my sump fills a tad bit up. I always error on the side of caution

 

[Scooby]

http://imgur.com/SoOTwmL

http://imgur.com/fObX2mm

http://imgur.com/kElC5FA

http://imgur.com/uT656NV

http://imgur.com/LWcjTTS

Sorry it's dirty from drilling. Let me know if you need other angles, I have a few others as well.

Well if you have a table saw cut the top of that over flow box and silicone the back of it to the tank. Done!

 

[cromag27 Verified Sponsor]

Silicone doesn't adhere well to plastics.

Well if you have a table saw cut the top of that over flow box and silicone the back of it to the tank. Done!

 

[mkunk1]

I'm willing to try a few options before getting a new tank - I haven't bought a sump yet so if I have to I will use this one and maybe use this as an excuse to go bigger before I even get started

I'd rather not cut the overflow unless that you guys think that will fix it. I'd rather just buy a new tank instead of both a new tank and a new overflow.

I'll try the least destructive option first and try that spacer plate that Shaun mentioned.... if you all think that would work. What material would work best? I was thinking I'd fill it and let it sit for a few days to see if it leaks. Then go from there?

 

[Scooby]

Silicone doesn't adhere well to plastics.

The silicone is not what's holding the overflow box... it's just there to prevent any water going on the backside. Use a rubber o-ring on the back of the box, In between the glass and the box. Don't cheap out on silicone it will work. That's if you go this route. GL

 

[blank]

Just wondering, dont they come with a template?

 

[cromag27 Verified Sponsor]

Irrelevant to my statement.

The silicone is not what's holding the overflow box... it's just there to prevent any water going on the backside. Use a rubber o-ring on the back of the box, In between the glass and the box. Don't cheap out on silicone it will work. That's if you go this route. GL

 

[Even Further]

Silicone doesn't adhere well to plastics.

In general yes, but there are specific silicone adhesives/sealants that will work for this application. Dow Corning 795 is one. There's a much longer cure time, but works just fine for an internal box.

 

[Scooby]

Irrelevant to my statement.

Bro, how do you think that glass tank is put together? Bubble gum lol
They used silicone to hold the plastic frame on top and bottom.

 

[Scooby]

Here's a 3 year old sump with dividers holding with silicone.

 

[cromag27 Verified Sponsor]

Yeah, I used to build glass tanks, and I currently build acrylic tanks. it's about using the right product based on the application. besides, the plastic trim used on tanks is a different material than the op's overflow box.

Bro, how do you think that glass tank is put together? Bubble gum lol
They used silicone to hold the plastic frame on top and bottom.

 

[cromag27 Verified Sponsor]

No. it's a neutral cure silicone, just like others used to build glass tanks. the cure time for all of these silicones is seven days +, depending on bead size. anything labelled as cured after 24 hours is labelled incorrectly. not only should you wait until after the cure time, but also the full strength set time.

But, even commercial grade silicone do not adhere well to plastics like acrylic, not because of the silicone, but rather the oily nature of certain plastics.

In general yes, but there are specific silicone adhesives/sealants that will work for this application. Dow Corning 795 is one. There's a much longer cure time, but works just fine for an internal box.

 

[ihavecrabs]

I'm willing to try a few options before getting a new tank - I haven't bought a sump yet so if I have to I will use this one and maybe use this as an excuse to go bigger before I even get started

I'd rather not cut the overflow unless that you guys think that will fix it. I'd rather just buy a new tank instead of both a new tank and a new overflow.

I'll try the least destructive option first and try that spacer plate that Shaun mentioned.... if you all think that would work. What material would work best? I was thinking I'd fill it and let it sit for a few days to see if it leaks. Then go from there?

I would cut down the top of the overflow. If you ever have an algae issue and it clogs the teeth, the water will go up and over the tank trim before overflowing into the overflow in your current situation.

I'd cut it down so it is 0.5" below the top of the trim in case of emergencies

 

[mkunk1]

Well I went out to fix it up and when I put the back box on I noticed that too was up on the trim keeping it from sitting level. I'll just plug this one up and use it as a sump and get another.

What is the best layout for a sump? I was thinking (left-right) sock filter/protein section with that baffle cut in half to get flow going through the middle instead of just over the top, to the fuge, then bubble trap going into the return. Any suggestions?

 

[cooper5389]

Hey, I might be crazy but I think there's a chance you might be overthinking this. Find somebody with a tablesaw and have then cut an inch or two off the top of your overflow. Just measure and make sure you cut enough off so it'll fit nicely below the trim on the aquarium. You'll have to cut new teeth in the overflow to lower the water level a bit but that shouldn't be too hard.

Remember measure twice... cut or drill once!

Good luck!

 

[Shaun Sweeney]

Sump layout depends on available space. I've just moved into the basement with unlimited space so my "sump" is actually 3 tanks and I'll be adding a turf farm.