Converting bottom drilled tank to Coast to Coast

[thax]

Im thinking of buying a 180 that has 2 overflows. Is there any way to ues the holes that are already drilled for a Coast to Coast overflow? Or would i have to ripe out the old overflows and dril the back? assuming thats what i have to do how hard is it to remove the overflows?

[uncleof6]

Originally Posted by thax

Im thinking of buying a 180 that has 2 overflows. Is there any way to ues the holes that are already drilled for a Coast to Coast overflow? Or would i have to ripe out the old overflows and dril the back? assuming thats what i have to do how hard is it to remove the overflows?

We have had a great deal of discussion on this question. You can put in a bridge between the overflows, but it has to be such that it free flows, with no water fall, from the center "section" into the original overflows. In effect, this creates a single overflow. It is a lot of work.

Taking out the overflows is also a lot of work, and then you end up with pipes running the height of the tank, exposed.

Certainly, pulling out the overflows, plugging the holes, and going out the back would probably be the best option, but again it is a lot of work.

[fishgate]

I'd keep the overflows and do 2 herbies like I did with almost the same setup. A coast to coast does not gain you much, if anything, in your setup since your two overflows wrap around creating more surface skimming area.

[McPuff]

The built-in overflows that you have DO take up a bunch of space and if the tank were empty I'd say remove the overflows, seal the holes, and drill the back for a custom overflow setup. Sounds like the tank is full though, so I'd say avoid doing anything other than maybe switching to a Herbie style drain system as suggested above.

[thax]

Originally Posted by uncleof6

We have had a great deal of discussion on this question. You can put in a bridge between the overflows, but it has to be such that it free flows, with no water fall, from the center "section" into the original overflows. In effect, this creates a single overflow. It is a lot of work.

Taking out the overflows is also a lot of work, and then you end up with pipes running the height of the tank, exposed.

Certainly, pulling out the overflows, plugging the holes, and going out the back would probably be the best option, but again it is a lot of work.

Do you have a link to that post? I was thinking about doing the bridge thing. Seames all i would have to do is cut 1 side off each over flow and cut a strip of acrylic across the front and bottom and then gule the L together then gule it to the over flow and silicone it to the glass in the back?

And to the peple that said said c2c dont help that much i thought they where amzzing things and helped a lot with skimming? My current tank only has 1 overflow and it always has a film in the corners.

[fishgate]

Originally Posted by thax

Do you have a link to that post? I was thinking about doing the bridge thing. Seames all i would have to do is cut 1 side off each over flow and cut a strip of acrylic across the front and bottom and then gule the L together then gule it to the over flow and silicone it to the glass in the back?

And to the peple that said said c2c dont help that much i thought they where amzzing things and helped a lot with skimming? My current tank only has 1 overflow and it always has a film in the corners.

I said C2C will not give you much more surface skimming than the 2 individual overflows. Good surface skimming is a critical function.

The bridge idea is ok, but a LOT of work for very small gains, and now an additional homemade bridge between the two overflows to look at. Also you will eventually develop leaks where the silicon connects your bridge to the glass and probably also the plastic overflow weir. Make sure to account for that extra water in your flood mitigation planning. But I guess if you are bored why not?

[Lsufan]

No matter how u modify it there is going to be a good bit of work involved. I would eighther leave it how it is or take the boxes out, plug the holes & come out the back with your plumbing. I love having a c2c box & I love a bean animal drain setup so I know I would plug the holes & eighther build a internal c2c box out of glass or my preferred setup which is a DIY ghost style overflow.

[uncleof6]

Originally Posted by thax

Do you have a link to that post? I was thinking about doing the bridge thing. Seames all i would have to do is cut 1 side off each over flow and cut a strip of acrylic across the front and bottom and then gule the L together then gule it to the over flow and silicone it to the glass in the back?

And to the peple that said said c2c dont help that much i thought they where amzzing things and helped a lot with skimming? My current tank only has 1 overflow and it always has a film in the corners.

We went over this on several occasions, (bridging overflows) in the main Bean Animal thead. Pulling the specific time frame, or specific posts would be almost as bad as the amount of work it would take to convert a tank with dual overflows, to a Coast to Coast, as described by Anthony Calfo (one of the chief proponents of the design that does bear his name.)

But it (bridging) is indeed a lot of work. There are also a number of technicalities that need to be observed to get the most of such a system.

The gains to "gain" are rather significant when moving to overflows without teeth, and with increasing the overall length. I don't know why folks try to infer that the gains are marginal, minimal, what have you. But when taken as a whole, (this line of thought can get complicated fast,) any argument against the work vs gain, are rather moot. The physics tell us the increases are "huge." But whenever physics is mentioned, you lose half the audience immediately, because the concepts are very technical in nature. Most agree that surface skimming is a big deal. What gets lost is the speed factor, and how that speed factor influences the gas exchange overall, and the operation of your skimmer, and the operation of all auxiliary systems, which is where it gets complicated. The short non-technical version is the faster the surface is renewed the better the gas exchange, and the more efficient the skimmer works, and it dominos from there. You can also silence a nosiy overflow (not drain; overflow) by eliminating the teeth, and increasing the length. Teeth are a part of the problem with "reef ready" type overflows as well.

I hear about 'real estate' when discussing C2C overflows, but really overflows such as you have take up more real estate, because the C2C does not go to the bottom of the tank, rather resides in the top part of the tank at the back. Basically unuseable space anyway. I think that the increases in efficiency, far outweigh the visual impact of a C2C. You see the back of the tank, or you see the face of the overflow, and the back of the tank...

[iced98lx]

I pulled mine out, used bulkheads to plug the holes and installed a new overflow. I did not do c2c but the principal is the same. It's doable but work obviously.

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[Joe0813]

I'd like to do what the video did for my 180. Seems silent compared to mine

[Sinn Sage]

Originally Posted by thax

Im thinking of buying a 180 that has 2 overflows. Is there any way to ues the holes that are already drilled for a Coast to Coast overflow? Or would i have to ripe out the old overflows and dril the back? assuming thats what i have to do how hard is it to remove the overflows?

Since you have not purchased said tank, why not buy a plain 180G tank and then just drill the holes you want out right and not have to worry about this and that?

[Bryan3536]

Originally Posted by iced98lx

I pulled mine out, used bulkheads to plug the holes and installed a new overflow. I did not do c2c but the principal is the same. It's doable but work obviously.

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Can you tell me how you plugged the bottom holes on your conversion? I am about to pull the trigger on a 180g in which I want to install a ghost overflow. I can get a used dual overflow and convert it, or get a new regular tank. Huge cost difference - $400+. I was going to bite the bullet and go with a new tank, but $400 is a lot of salt, live rock, fish, etc.

[McPuff]

Originally Posted by Bryan3536

Can you tell me how you plugged the bottom holes on your conversion? I am about to pull the trigger on a 180g in which I want to install a ghost overflow. I can get a used dual overflow and convert it, or get a new regular tank. Huge cost difference - $400+. I was going to bite the bullet and go with a new tank, but $400 is a lot of salt, live rock, fish, etc.

Just get a piece of glass that will be the same thickness as the bottom panel on the tank. Make sure that piece of glass will sufficiently overlap the holes (+2" on each side of the hole edge) and then silicone the cr@p out of it. Once this is done, you can drill your own holes for whatever overflow you decide upon. Definitely worth the $400 savings in my opinion.

[iced98lx]

Originally Posted by Bryan3536

Can you tell me how you plugged the bottom holes on your conversion? I am about to pull the trigger on a 180g in which I want to install a ghost overflow. I can get a used dual overflow and convert it, or get a new regular tank. Huge cost difference - $400+. I was going to bite the bullet and go with a new tank, but $400 is a lot of salt, live rock, fish, etc.

I put bulkheads and plugs in the holes.

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[ca1ore]

I prefer the glass patch approach, though it's essentially a permanent fix. I don't like having bulkheads that are 'open' to the full volume of the tank.

[ReefkeeperZ]

if your gonna rip em out go ahead drill the back, (have to agree with ca1ore, on the glass patch for permanence, better reliability) or you can bulk head it but long term it is a potential problem to face with a stocked then established tank.

there's no super easy swap out but it's not really that horrible either since your already looking at removing the BFT (big fXXXX thing) in the way of your real estate. you might as well spend the hour on it to really patch it and drill the back, the wait the 24 for everything to cure. one day way less headaches later.

[tkeracer619]

Def use glass patches with silicone like momentive rtv.

[Bryan3536]

Originally Posted by tkeracer619

Def use glass patches with silicone like momentive rtv.

What about 3M 5200 Marine Adhesive? I’m a boater and know that stuff is solid and permanent, though perhaps not ok for tank use.


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[tkeracer619]

It's reef safe once cured but I would stick to a silicone that tank builders use.

[lapin]

I had a 125 that was drilled on the bottom for an overflow. I did an external coast to coast to replace it. I used the bottom drilled holes for the intake of a closed loop rather than patching them. Inside the tank I placed a 90 in the bulkhead and used one of these to keep stuff from going thru the loop. Put some rock in front of it and you could not see it.
http://www.dursostandpipes.com/store...-1.25-inch-pvc