Who here uses an external overflow box?

[greenmaji]

There seems to be alot of concern about external overflow boxes compared to internal overflows/drilled tanks.. I have my own opinions but I would like to hear others opinion on this subject.. And If you did decide to go with external overflow boxes why you were not overly concerned about using it.. TIA

[Brad]

I retrofitted a sump to existing, operating tank. Draining the tank for drilling would have been too stressful, so I hung an overflow on the tank. It has worked reliably for 2 years so far.

[dax29]

Have you had any power outages during that time?

[mykpoz]

living in florida, I have had several power outtages...

as long as you plan right, with enough overflow room in your sump, you shouldnt have a problem... most overflows that I see on the markets today do not break teh siphon during power loss...

[MarineFlake]

I have used an overflow box for over a year with no problems. I have literally watched as the power was turned off both in testing and due to 'Acts of God'. If you have your overflow setup proper, you will have no issues with everything starting back up. Its simple physics. To prevent back siphoning, you simply drill a hole in you returns, about 1/8" or so should do about 1" under the water surface. This will break the siphon and prevent a sump over flow. The 'gurgle' of an overflow is probably the most annoying thing. I have a lot of experience with mine, so I am able to tweak it out so it is all but perfectly silent.

GL

[HoopsGuru]

Lifereef overflow here. I wanted a sump, and was not comfortable with drilling the tank in the middle of the living room with a Dremel due to the mess. No problems thus far and I agree with the above that with precautions you can reduce the likelihood of problems.

[Dr.Nate]

I love my CPR overflow.......

reasons why I didn't drill were the same as everyone else....didn't want to drill it after the fact.

[Hara]

I use an external on my eel tank and have never had problems, I also have 4 j tubes stuck in there instead of the usual 2. (just to be on the safe side) I lose power about as often as I get my mail. So far so good.

[Brad]

I've lost siphon on a few occassions, but they are almost always my own foolishness. I've never lost siphon simply due to a power failure. Usually, I mess it up when I'm sticking my arm in and out of the tank causing the tank level to rise and fall quickly.

[dax29]

I imagine that siphon loss problem is not the same on a 180 gallon. I am planning on putting my sump (29 gallon tank) in a larger rubbermaid-type container to catch possible overflow. Does that sound like a good idea?

[greenmaji]

I personally think that the siphon loss problem has nothing to do with the size of the tank. Having a siphon overflow that is far too big for your pump causes problems but from the conversations I have had with you dax29, I think if anything you would have the opposite problem(trying to push the limits of the overflow box).

[afilter]

Very timely discussion. I am looking at purchasing a new tank this weekend and am debating on overflow or not. I am not sure I am ready for a sump yet, but now would be the time.

Everyone responded that they did not drill because there system was already set up. If you could do it again would you have bought a tank already drilled vs HOB overflow?

[dax29]

Good question. I've heard that overflow boxes are afterthoughts. The cost of the pre-drilled tank is what is killing me.

[afilter]

Yeah, I have been pricing tanks and getting a pre-drilled adds about $80 with the overflow kit and good overflow boxes run $100-150.

[dax29]

So you are running about $180-230. My quote from glasscages added $120.

[afilter]

I priced an All Glass 90gal (Pet World Warehouse) with single mega over flow for $226 w/o mega overflow $193 add 49.99 for the overflow kit(plumbing). Total to get drill overflow $83 more than the non drilled Tank.

In this area Pet World was far cheaper than anyone else on their tanks though and they advertise lowest price guarantee. Better yet, they keep them in stock from 10g-180g and will special order anything else.

I think I am going with the 90G with overflow even tough I am not ready for a full sump/fuge I will just run a rubbermaid tub in the meantime.

[Phyl]

It is a good idea, but optimally your sump should handle all back siphon. That's the case whether it is done through an external or internal overflow though. I do have a low flow float switch in my sump though to prevent water on the floor should the overflow fail. That switch has saved me a couple of times. Once the drain hole out of the overflow box got clogged and once the airline tubing ended up getting air in it. I think I could put an aqualifter pump on the airline to prevent siphon loss but since I have the float switch I've never bothered to look into it.

Still not a perfect world, but I test it often.

Also, make sure that you clean out those air holes (once a month is a good idea) to make sure that gunk doesn't build up in there and cause the airhole to fail to break the siphon in the event of a power failure.

As for not being ready for the sump you could always cap the overflows so that they didn't... overflow. Then when you're ready open up and go from there.

I would never purposely buy a non-drilled tank, even if it was 200$ more expensive. It is SOOOOO worth it.

[MyMonkey]

Sorry to bring this thread back into play but I am now looking into starting up a Sump/fuge. My concern is not with the siphon overflowing the fuge in the event of apower outage but the power coming back on and overflowing the tank when the return pump returns all that water. If the siphon broke, then would'nt the tank overflow? Trying to avoid this. Any suggestions?

[pelochas]

you can put a float switch on your main tank to turn off the return pump.

In a perfect world, the CPR overflow will still have siphon if the sump is full and the tank is low. when power returns, the water levels rises in the main tank, and the overflow will continue to siphon the water to the sump.

http://www.melevsreef.com/what_sump.html

i have the standard overflow box with the U tubes. I cant keep a siphon going if the tank goes low and the sump goes full. if power returns, my tank may overflow. havent tested it yet, should of done this outside before setting the whole thing up.

i going to either buy the CPR overflow box or somehow mod mines with the aqualifter.

[MyMonkey]

Now I see. Thanks for the link. Now I understand how the sipphon starts back up when the pump turns back on say, after a power failure. Finally.