Are External Overflows Safe/Reliable?

Shep · Sep 12, 2015

Just finished setting my tank up and was thinking about adding a small sump to the tank but do not really want to drill the tank. How safe and reliable are external overflows, do I need to worry about power outages? Thanks! Also brand recommendations would be appreciated as well.

Reab · Sep 12, 2015

I picked up a overflow box from a friend, made by lifereef. I have tested and with simulated power outage, as long as there is enough room in sump for the water, you will not have a problem. where you run into trouble is if the siphon breaks. this happens when air gets trapped in the u tube and causes the siphon to fail. I have had this box set up for over a month and even when i introduce bubbles to it, they always get pushed through. Many people will tell you to purchase an aqualifter by tom, and attach it to the u tube. do NOT do this, it is yet another piece of equipment, that if fails can cause more problems than it prevents.

http://www.lifereef.com/

Shep · Sep 12, 2015

Thanks! i will take a look at that brand

Reab · Sep 12, 2015

Also, siphon in this one remains when power is out, so once power resumes, siphon is intact and continues to flow

Reab · Sep 12, 2015

This one has the silencer and is quiet. I hear my return pump more than it

kschweer · Sep 12, 2015

They're not as "safe" as an internal overflow box in my opinion, but if you get a good brand and understand how it works and any flaws it may have I think you will be fine. As long as they are set up correctly they aren't too bad.

Reab · Sep 12, 2015

kschweer said:
They're not as "safe" as an internal overflow box in my opinion, but if you get a good brand and understand how it works and any flaws it may have I think you will be fine. As long as they are set up correctly they aren't too bad.

I agree completely, and if i had the means to drill my tank, believe me i would have! but alas such is not the case. any overflow can become clogged so we should all keep a vigilant watch on our overflows

hybridazn · Sep 12, 2015

I ran a hob overflow way back when, a cheap eshopps one. As long as you dont break the siphon in the U-tube it will be fine. Most hob boxes make it very hard to break the siphon short of pulling the tube out. i would shut the return pump off quite a few times per week and it always started right back up without a hitch

bayoupr · Sep 12, 2015

I used to run a Lifereef dual overflow and never had a problem with it in the 4+ years that I ran it. My new tank has a built on one, not internal but similar to the lifereef except no inner box or u-tubes (teeth are cut into the back wall of the tank which is acrylic and the outer box with the drains are glued onto the back of the tank). I would not hesitate to run another Lifereef overflow on a tank.

Waters · Sep 12, 2015

I have used them for years (shutting them off once a week and restarting without any siphon break for water changes) without any issues. I always used the Eshopps brand. As long as you set it up correctly, it is pretty fail proof.

Stephanie11 · Sep 12, 2015

I had 2 eshopps on a 90 gallon. I still have them. I live in Maine. Power likes to find its way out in he winter! I never had a problem in the two years I ran that tank. You need to make some silencers. Easy. If I recall hoffman gurgle busters! I run drilled tanks now. I will never turn back.

MrDJeep123 · Sep 23, 2015

DIY PVC overflow, if you will. It was extremely easy to make. I use an aqualifter to maintain siphon because sometimes at random it looses it. I've had it on the tank for a year now and I can't say that I've had any issues. The total cost was about $20-30 for all the supplies.

jd371 · Sep 23, 2015

I have a eshopps on my 75gal. No issues so far. Even when I shut the pump down for a water change, the siphon starts right back up again when the pump is turned on.

smh254 · Sep 23, 2015

I have a eshopps overflow box for 18 months and never had a siphon break. I've never had an internal overflow so I don't know much about them. I like the one I have because it's very easy to clean and move around if needed.

Shep · Sep 23, 2015

My biggest fear with them is flooding due to power loss, how much of a risk is this?

smh254 · Sep 23, 2015

That y u test them first. My sump is Big enough to hold the extra Water. The last chamber of my sump is the only thing that would get pumped back in my tank of the siphon breaks and my tank can handle it.

Shep · Sep 23, 2015

Good to know! I might just have to look into setting one up.

squillaempusa · Sep 23, 2015

Reab said:
I picked up a overflow box from a friend, made by lifereef. I have tested and with simulated power outage, as long as there is enough room in sump for the water, you will not have a problem. where you run into trouble is if the siphon breaks. this happens when air gets trapped in the u tube and causes the siphon to fail. I have had this box set up for over a month and even when i introduce bubbles to it, they always get pushed through. Many people will tell you to purchase an aqualifter by tom, and attach it to the u tube. do NOT do this, it is yet another piece of equipment, that if fails can cause more problems than it prevents.

http://www.lifereef.com/

if he doesn't use the Airlifter pump he's going to have to suck the air out of the top of the overflow box or U-tube every now and then, or the syphon will eventually break. usually you can tell when it's time to suck air out by the water level in the intake portion of the overflow box. the water flow will start to slow (due to air taking up space), raising the water level in that portion. this is the warning that there's too much air bubbles building up, and the tank is about to overflow if the air is not sucked out within a day or so. i used to get the air out as soon as the level was slightly higher than normal just to be safe. it was a long time ago, but i think it was about every 4-5 days. if your bubbles just flow through the top of the box and not build up, that is rare, and we can't assume that'll happen for most people.

i have dealt with this process for many years, and it sucks. if you go away for a few days, there's a good chance your tank will overflow if the person watching it doesn't know the routine. the Aqualifter was a "godsend" for me and have been using one for several years now. it needs maintenance once in while of course. i purchased a couple diaphram sets from BRS for like $2-3 each (plus shipping). if it fails (so long as tubing and airlifter remain airtight), the water level in the front portion of the box will slowly rise, just like it would with no airlifter when the air builds up.

Reab · Sep 23, 2015

I have never had a problem with air building up. Could be design or utube. Not sure. If it took less than a week for the air to build up I would invest the $15 for an aqualifter. If so. Purchase the little prefilter for the pump, that will help prolong the pumps life, and install a check valve.

DeniseAndy · Sep 23, 2015

I have made three DIY overflow boxes for my 5g, 6g, 40g. They work great, but I always use two tubes (u tubes) in each in case one fails. I have tried both having an air valve and not and prefer to not. I have had one fail but that was before I put two tubes in and was due to me not paying attention and the air valve combination.

Power outage never an issue if correctly made. Only thing is air does eventually get into the tube. I use clear tubes so can see it. When it builds, I stick some air tubing up and suck it out. Done. So far it has been over two weeks since I have needed to do that, so it does take time to build up.

I was always reluctant until I read up on how they work specifically. That may help you decide. If you know the physics it helps a lot.