Anybody using a Calfo overflow?

[Derry]

I'm in the early planning stages of a new tank, and I'm interested in doing a Calfo instead of a full-height overflow. I'd love to hear from those of you who are using them. Please give me the pros and cons in your experience, and photos would be a bonus! Of particular interest would be anyone who has cut down the back panel of a tank in order to install an external Calfo overflow off the back of the tank.

[GKarshens]

I have used a Calfo style overflow. I put in a 30" wide overflow box only 1" deep in my old 125g. I then drilled a couple holes in the back of the tank and had an overflow box on the back to accomodate the plumbing. It worked perfectly. I like it because you get more surface area of the top of the water going into the sump to get skimmed by the skimmer. I can't think of any negatives.

[acropoorer]

I have dual calfo's on my tank. I just cut two 1" slots (drilled each end), but you could do a similar thing at the very top of the tank. I bought a wet saw with a diamond blade specifically for glass and some hole saws. If you need a saw I would loan it out if you need it.

I love not having the clunky looking overflow box in my tank and the waterfall doesn't fill up with algae like the teeth flows do. The only downside is that you have to have the space behind the tank for the box or boxes.

Here's some pic's. Instead of a slot, you could do a trough. The slot is just big enough to put my returns through. Also, I did a full 4 sided acrylic box so that I could color the back glass and not have it as part of the overflow.