Thinking about using a HOB overflow on my next tank

LobsterOfJustice

LobsterOfJustice

Recovering Detritophobe
So, am I crazy?

I have an AGA tank with a mega-flow now and it is unnecessarily large. It is difficult to access. It's plastic, so it is impossible to scrape corraline off of.

I am upgrading tanks during a move this summer, and I am thinking about going with a HOB overflow. They take up much less tank space, and you can place them wherever you want. It's not 20" deep, so if anything goes into it, i can actually get it out. And it has to be easier to keep clean than that monster in my tank I have now (at least HOB have flat sides).

I was looking at the LifeReef boxes... I have heard good things about them, and their website claims that they have never had a report of one failing to restart after a power outage.

Someone will inevitably suggest drilling the tank. This option is much harder. The hole can not be moved. I will have to take the tank to a local club member's house and pay them to drill it, as I do not have the diamond bits (let alone guts) to drill it myself. I also prefer the clean look of an overflow grate to an upturned PVC elbow. And keeping a PVC elbow clean is even harder.

Am I being stupid? Everyone seems to reccomend a drilled tank if at all possible. Does anyone else use a HOB overflow "on purpose"? Does anyone have a HOB overflow with no intentions of changing, even if you could start again? What overflow boxes have you found most reliable?

Thanks,
Mike
 
I use a HOB overflow on my 40 cuz i cant drill my 40 (its tempered glass). Its the only overflow i've had as of now, but on the 16g bowfront that i'm setting up it has an overflow that came with it. Its pretty much the exact same HOB overflow as the one i already have on my 40, just smaller. So i'll have 20 of them.

Both of them are the U-tube style ones. I havent had any problems losing the siphon when i turn off the pumps. The water level in the overflow becomes equal on both sides (the side that is in the tank and the side that hangs on the back, that is). When i want to restart it, i just turn on the return pump, wait about 2 seconds, and then poor a glass of the tank water into the back part of the HOB overflow (again, the part that is not in the tank) and it starts automatically.

Oh, one thing tho. I strongly suggest getting one of the silencers for them. On my 40 i dont have a silencer and at times its perfectly quiet, but the other half of the time you can hear the constant running water noise (and splashing).

The HOB overflow that i got for my 16 already had a silencer on it when i bought it (it was used) but i havent tried it yet.

Also, these are also plastic, so you cant scrape coraline off of them. Well actually i think you can if you get one of those scrapers made for acrylic tanks. I may have to try that now.....
 
What I have on mine also. Has never lost siphon. I take the inner box off once a week to try to keep it clear and it has been working well so far! Just a little pink in the corners.
 
I have a lifereef overflow on my 75 reef, and it's well made. With all HOB overflows, you have to clean the box inside the tank. The high flow between the "teeth" of the overflow lends itself to corraline and other growths that will inhibit water flow.
 
Sir_dudeguy, what happens if you aren't home when the power comes back on, and you can't pour that cup of water into the overflow?

Thanks for the replies. Anyone else?
 
If the overflow in the tank is in the right position, it will start as soon as water starts flowing in.
 
<a href=showthread.php?s=&postid=9344782#post9344782 target=_blank>Originally posted</a> by LobsterOfJustice
Sir_dudeguy, what happens if you aren't home when the power comes back on, and you can't pour that cup of water into the overflow?

Thanks for the replies. Anyone else?
Click to expand...

Maybe he was talking about if he has removed it to clean it or something like that. Any well designed overflow will not need a cup of water to get restarted after the pumps are turned off. I say go for it. I used HOB overflows for years without any problems and I'm still using one on my refugium. They can be noisey, but a little messing with them and a bioball or piece of rubble placed just right can quite them down substantially.
 
I still debate whether or not I will be using a HOB overflow (Lifereef only) for my next tank.

My understanding of HOB overflows is that, to make it as disaster-proof as possible, you need to have extra volume both in the sump and in the main tank. The sump needs to have enough volume such that if the return pump fails then any excess water will not overflow the sump. The main tank also needs to have enough space such that if the U-tube becomes blocked (snail/algae/sabotage), the main tank will not overflow if the return pump continues to run until it "runs dry."

My idea (suspect there are others as well) is to put the return pump in a tall yet narrow chamber or cylinder (5" pipe or something) which is fed by water flowing over the edge/top. That way, you can have a sump with a significant volume for refugia while still only pumping a few gallons back to the main tank if the U-tube jams.

2 other thoughts:

1) I have not seen a Lifereef Overflow up close, so I do not know if it would overflow in the second chamber if the down tube was jammed (this seems to me to be less likely that the U-tube being jammed, but it is worth considering).

2) You can also add a float switch to the sump, main tank, or both, where if the water level rises or drops below a certain point then the pump power is stopped. Float switches are also not failsafe, but they provide an added measure of safety.

Finally, I too have the option of getting a drilled tank, but will most likely be going with a HOB refugium and a HOB or in-the tank skimmer for sporadic use (mine will be a skimmerless system with macroalgae nutrient export).

Hope this helps!
 
The problem you describe with needing extra space in the sump isn't any different from an in tank overflow. Yes, you could run into problems if the U tube clogs or loses suction, but in almost 20 years I've never had it happen. I'm not trying to persuade you one way or another, just letting you know that a well designed HOB overflow can work very well.

Lastly, keep in mind that plants won't pull out the same things from your water that a skimmer will. They may keep nitrates, phosphates, and other things low, but there are plenty of other compounds they will not remove.
 
It's funny that you posted this because I am going through the exact same thought processes. My next tank is going to be a lot bigger and my original plan was to get an AGA RR. Then I saw a few set up and was surprised at how much space the overflows take up!

Personally I would rather have the space for aquascaping and swimming so I've decided to go with a regular tank and a Lifereef overflow. The only "negative" that people harp on with the Lifereef is cost, but I don't mind spending the money for a well-made, reliable product with great customer support.
 
I have 3 HOB's going on 3 tanks right now 1 FW 55gal, 1 FW 90gal, 1 Reef 44gal. 2 u-tube, 1 built in siphon. The built in siphon type is a pain unless you have a powerhead or lift pump connected to it, they tend to collect bubbles because they aren't really round. I've never had any trouble with the u-tubes at all. Be sure to drill a hole in the return line at the water level in the tank, otherwise a lot of water will siphon back into the sump when the pump turns off. You could also add an additional u-tube to safeguard against a clog (snail, crab, etc).
 
No you aren't crazy. When recently building up my new 90g, I specifically did not want a drilled tank, or one with a corner overflow.

I wanted a very clean look, with no powerheads in the tank. My only plumbing that shows in the tank is about 1-2" of loc-line outlets from my closed loop. I love it.

I have never had my HOB overflow fail in about 6 years. It is small, doesn't take up tank space for aquascaping and is quiet.

Here's a pic. From this view, you can't see any of the pluming or overflow. I like it a lot without the big corner or center overflows, or the big bulkheads.
90gtankb.jpg


Dan
 
I use a HOB overflow on my 29 Gallon tank. As long as you take the necessary precautions, and have a good quality overflow....you really shouldn't have any worries.


To prevent clogging of my U-Tube I just simply added another tube to my box.
 
I've got a lifereef. Rock solid.

I really wouldn't recommend putting a second U-Tube in your overflow box, however. U-tubes need to have enough flow pushed through them to keep bubbles from accumulating at the "U". If you put in a second tube, you end up running much lower flow through each tube.
 
yea i have a CPR type overflow and it's a pain, you'd think they'd be easier to deal with, but the u-tube is much simpler and lower maintenance.
 
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