How safe are HOB overflows?

[dwculp]

I have a 100 gallon (60" long)FOWLR tank. I had always thought about drilling it out for overflows but at this point, I know that will never happen. I would need to drain the tank, put the rock and livestock somewhere etc...

Currently for filtration I use a large canister filter, that actually works well but I would like to use a sump so I can hide some of the equipment in it (heater, ATO, put in a protein skimmer etc).

How safe are HOB overflows? Any recomendations?

[BossHoggin]

C-siphon by cpr has worked well for me. Far more reliable than the u-tube ones, never break siphon. Just keep an extra aqualifter pump on hand

[Reeferz412]

If you want a fail safe overflow, go with lifereef. I have never heard of one failing.

[degibson84]

I have been using an eshopps for about a year with no issues. Every time I unplug the pump and plug it back in it never loses siphon. Lifereef is great but the price is way too expensive compared to eshopps

[swk]

I prefer the u tube style overflows cause they don't depend on a pump to work. I've had eshopps running for 18 months w/o losing suction.

[Wills612]

Originally Posted by swk

I prefer the u tube style overflows cause they don't depend on a pump to work. I've had eshopps running for 18 months w/o losing suction.

X2, I've used U-tube style overflows off and on over the past 5 years. Eshopps are cheap and work great, LifeReefs are higher quality and work on the same principle. As long as you have the proper flow going through your U-tube to keep air bubbles out, the overflow its self will not fail.

[juice79]

I had and eshopps utube style HOB that ran on my tank for 2+ years before I broke down my previous tank. Never broke siphon from the day I set it up.

[slush]

Cpr worked for me with no problems but just make sure you have a spare aqualifter pump incase it quits working.

[Drae]

The cpr is far superior to the u-tube siphons imo.

[Wills612]

Never used a CPR, what makes them superior?

[saltfishguy18]

Go u-tube before a CPR. The cpr's are a great concept but unfortunately when algae starts building up inside the box it slows flow down and it's super hard to clean out. Plus like previously stated they depend on a pump to keep a constant siphon. I have used u tubes many of times on older tanks (my current tank is drilled now so no need) and they always hold a siphon; never had a single issue. Word of experience one of my buddies is a fellow reefer and he likes the concept of a cpr box so he purchased his second one (he had one on an old tank but broke that tank down years ago). He had the same issue he had before, algae builds up and slows the flow down and relies on a pump to keep it going. Just like last time he went back to a u tube box. We just moved his tank and he want back to the old fashioned u tube.

[Drae]

Originally Posted by Wills612

Never used a CPR, what makes them superior?

The aqua lifter pump hooked up to it basically. It works without the pump but the pump gives it some redundancy. The u-tube siphons need to be re-primed if they sit for awhile with no flow ( an hour or so) and the cpr with the aqua lifter is self priming.

[kv2wr1]

When I had my 40B, I used a lifereef HOB overflow box and it was great. It never lost the syphon ability even when the power went out for hours at a time. I never tried the CPR so I can't comment on that.

[geomarq]

Agee on the CPR statement.. it flows without the $15 pump as I clearly found it when the pump died.

[sirreal63]

The CPR weir is the very epitome of a flawed design. Any product that requires another product to ensure safe operation is a poorly designed product.Over the years more floods have been attributed to a CPR than any other brand out there. The Aqualifter is another weak point, they work good in the beginning but it is a matter of time before it looses suction, the line clogs with algae or completely fails requiring a rebuild. Where will you be when it fails? If at home no biggie, but if you are away from the tank it can be an issue.

The U-tube design does not rely on any band aid to correct the poor engineering. Properly set up it will not lose suction, the tube will not lose water and any bubbles that appear will flow through it. It can be problematic if not set up correctly or too weak of a return pump is used, but these are not design flaws, they are user error.

I used hang on back overflows for many years, I never had a failure that wasn't because I did something stupid. I researched all of the different hang on overflows before I decided on the U-tube design. The number of failures of the CPR/Aqualifter design used to be fairly well known, you will find a lot of them in the archives here.

[Blown 346]

I have both the CPR with the lift pump and the U tube style. I honestly like and trust the U tube siphon over the CPR lift pump style. I think the main reason is I had trouble with the CPRs lift pump, on more than one occasion and water on the floor more than once with it. The lift pump would either stop working and I had to take it apart and mess with the magnets inside it, or I would find water inside the lift pump. It honestly only worked for me flawlessly for a little over a year before I had to replace the lift pump, plus those things get pretty warm running all the time. The U tube design is free, no power usage and no heat.

My U tube style I have never had a issue with. Yea I have to clean the tubes every so often, and manually start the siphon with a air line but that takes less than 4 minutes to do. I have never had a siphon break, or any flooding with the U tube styles. Then again I run all PVC returns and have a siphon break in the return so the siphon stops once the water level in the tank drops. But he u tubes always hold water like they are supposed to.

[lcs]

^^+3

I have had the Eshopps U tube overflow on my tank for going on 4 1/2 years without any problems I didn't cause myself. I've had the power go out at night and the siphon started right up as soon as the power came back on. The only maintenance is I soak the tube in vinegar every once in a while to clear it of algae and other sludge that builds up. I've had it hold the siphon even with a significant bubble at the top of the U tube.

[FlyPenFly]

Lifereef.

For a bit of extra safety, I would get this http://www.coralvue.com/fw110-high-a...e-float-switch

That'll cut your pump if your water level ever rises unsafely and will prevent a huge expensive disaster.

[FlyPenFly]

Originally Posted by Drae

The aqua lifter pump hooked up to it basically. It works without the pump but the pump gives it some redundancy. The u-tube siphons need to be re-primed if they sit for awhile with no flow ( an hour or so) and the cpr with the aqua lifter is self priming.

No they don't. I had a life reef and it sat with no flow overnight, didn't lose siphon.

The CPR/RO hob design is a horrible idea.

[Drae]

Originally Posted by FlyPenFly

No they don't. I had a life reef and it sat with no flow overnight, didn't lose siphon.

The CPR/RO hob design is a horrible idea.

If it's so horrible then why did mine and plenty other peoples work flawlessly for years without a single problem? I've never used life reef but the eshopps overflow loses siphon.

[FlyPenFly]

The eShopps overflow quality is inconsistent for sure.

A lot of people use a Herbie overflow without an emergency... some won't flood, some will. Doesn't mean it's a good idea.

[MondoBongo]

Originally Posted by Drae

The u-tube siphons need to be re-primed if they sit for awhile with no flow ( an hour or so) and the cpr with the aqua lifter is self priming.

i've never seen or experienced this. the u-tubes on my overflow boxes stay primed for as long as i leave them be. there is a secondary weir on the "dry" side that keeps the water level up and ensures it does not lose siphon.

i have two e-shoppes overflows, neither have this issue.

as sirreal63 said, the cpr is deeply flawed. i don't want a rube goldberg device to start my overflow siphon.

[wildman926]

Originally Posted by sirreal63

The CPR weir is the very epitome of a flawed design. Any product that requires another product to ensure safe operation is a poorly designed product.Over the years more floods have been attributed to a CPR than any other brand out there. The Aqualifter is another weak point, they work good in the beginning but it is a matter of time before it looses suction, the line clogs with algae or completely fails requiring a rebuild. Where will you be when it fails? If at home no biggie, but if you are away from the tank it can be an issue.

The U-tube design does not rely on any band aid to correct the poor engineering. Properly set up it will not lose suction, the tube will not lose water and any bubbles that appear will flow through it. It can be problematic if not set up correctly or too weak of a return pump is used, but these are not design flaws, they are user error.

I used hang on back overflows for many years, I never had a failure that wasn't because I did something stupid. I researched all of the different hang on overflows before I decided on the U-tube design. The number of failures of the CPR/Aqualifter design used to be fairly well known, you will find a lot of them in the archives here.

Very well said, as always when getting advice from sirreal63.

I have always U tubes for overflows, and don't like drilling glass. Something about that just sends off alarms in me.

For a fail safe setup, get a pump stopper kit from Aquahub. HERE is where you can see it. I use them on both my tanks, modified for my use.

[AkoAung]

Originally Posted by swk

I prefer the u tube style overflows cause they don't depend on a pump to work.

Originally Posted by slush

Cpr worked for me with no problems but just make sure you have a spare aqualifter pump incase it quits working.

Originally Posted by Blown 346

I think the main reason is I had trouble with the CPRs lift pump, on more than one occasion and water on the floor more than once with it. My U tube style I have never had a issue with. Yea I have to clean the tubes every so often, and manually start the siphon with a air line

Gentlemen! I read this thread because I recently purchased a CPR overflow with the airlift. I thought the lift was to get the siphon started initially but as you all stated, it has to be running all the time for the CPR overflow to work. And I am concerned about the worst case scenarios about airlift stopping and water overflowing when I'm not home. I've come up with a simple solution to this.

CPR is a U-tube siphon without the one-way air valve. The simple solution is to attach a one-way air valve to the CPR with the use of a short tube and use the other end to create the siphon. Once the siphon is established, then remove the air lift from the one-way valve and presto. you have a U-tube overflow box.

Using the cheap <$0.99 one way air valve wouldn't even require purchase of an air lift. And CPR would need to be cleaned, just like U-tube overflow boxes in case of algae buildups. Sounds good?

[sirreal63]

The problem isn't initial starting with the weir, it is continued use and air bubbles do not flow through them correctly, they tend to collect in the corners, as they collect less area is available for flow, reducing the flow until the tank overflows. Bubbles are normal and expected. The CPR design allows for a lesser flow at the corners, which is where any bubble will collect.