HOB overflows?

[Ccote]

I’m sure this topic has been beaten to death but Im curious about hang on back overflows and how often they fail. Am I asking for a disaster? Any tips on what brands work well? Any return pump suggestions? I’m just a blue collar guy with a small budget to work with. Thank you for any help! This place is so awesome

 

[fishguy242]

hi i am pretty sound with eshopps overflows,pump??? too many to choose i use mag drives,would recommend controllable jebao ,happy reefing and welcome to the reef going to love it here

 

[KJ]

Welcome to R2R!!!

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If you have aquarium equipment questions or ideas this is the place to do it. Discuss aquarium pumps, filters, skimmers, refugiums, reactors, and much more.

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[Retro Reefer]

Welcome to R2R! HOB are fine but they need to be set up properly.

 

[Special K]

I use cpr overflow with a sicce pump and no complaints so far

 

[Brandon Smith]

 

[Hemmdog]

Welcome to reef2reef! Drill the tank, much easier. HOB overflows will fail eventually, it’s just a matter of when.

 

[cloak]

I can't remember which brand I have, but I've been using the same HOB overflow on various tanks now for about 20 years without a failure.

 

[Peace River]

Welcome to R2R!!! I expect that you will get a range of answers and experiences on these overflows. I have had a older CPR HOB overflow that I use on a tank in my garage and have a couple of issues over the years. Personally, I would not trust it on a tank inside my house.

 

[dbl]

Welcome to R2R and thanks for signing up. No experience to offer with HOB's.

 

[Billldg]

Welcome to R2R!!! I will stay out of this discussion as you will in fact get several different answers, LOL!!!

 

[Scotty Buttons]

I've used them for many years. If there set up properly as well as your sump then there really is no way to have a failure. If it's set up right then the overflow can only drain water from the tank to the lowest point on the overflow. And if your sump is set up properly it can only fill up with as much water as the over flow drains from the tank. Kind of checks and balances system.

 

[malacoda]

Welcome to reef2reef! Drill the tank, much easier. HOB overflows will fail eventually, it’s just a matter of when.

That's a pretty bold assumption to make. I'm sure there are plenty of people who have been using them for years without a problem. One could just as easily say sooner or later any bulkhead will leak.

Properly set up and maintained there is no reason to expect a HOB overflow to fail.

Personally, I've been using a Marine Depot HOB nano overflow on my 24g for nearly 5 years without any issues whatsoever.

 

[Ccote]

Any suggestions on the amount of overflow flow I’d need for a 29 gallon?

 

[BeejReef]

Welcome from another budget reefer. Long term, I'd hazard to say drilled will cost less, but peeps do it well w hob

 

[southerntnreefer]

Welcome to r2r! I've used eshopps in the past, and just now prefer drilled tanks. I had one on my old tank and never had any issues. N


Make sure your sump can take the extra water if you loose power, and build some gurgle Buster's, and install a valve and your in good shape.

 

[malacoda]

Depends how much turnover you want from the DT thru the sump.

Since in-tank power heads provide most of the DT flow these days, many people tend to go with of 3 to 5 times the DT volume passing to the sump each hour. 29g x 5 = 145gph. So a Marine Depot Nano HOB Overflow or a Eshopps PF-nano would do just fine.

If you want to run with a higher rate of turnover, say 5-8 times DT volume/hour, then it's probably be better to go a size up: either a MD OF-300 or Eshopps PF-300.

 

[piranhaman00]

Welcome to reef2reef! Drill the tank, much easier. HOB overflows will fail eventually, it’s just a matter of when.

Everything fails eventually, a drilled overflow will fail eventually as well. They just require extra attention.

I run hob without any thought.


OP look into life reef

 

[Crustaceon]

I’m currently using a hob eshopps pf-1000 siphon overflow and will be drilling my tank for an eshopps prodigy tomorrow. The reason is while siphon overflows can go months or even years without problems, I’ve been lucky enough to catch mine acting up several times. What i’ve found is most of them have a fatal flaw. It’s the u-tube. Pretty much all of these overflows come with a u-tube that’s too big. While they theoretically can support a lot of flow, that flow is massively slowed down once it leaves the tank and enters the rear chamber of the overflow. This creates three problems: The first is the overflow is at the mercy of the drain attached to the overflow box. If you want a quiet drain, you’re going to slow down flow OR raise the water level in the rear chamber, which places backpressure on the u-tube outlet, slowing flow. This creates a secondary problem of potentially overflowing the tank if your pump puts out too much flow, even if the overflow box is rated for it. Keep in mind, these boxes are rated with zero backpressure in mind. This means they’re rated minus a slightly clogged foam or a durso in the rear chamber. No one runs their overflows this way because it’s insanely loud. The last problem is bubble accumulation in the u-tube because of it’s size and the above problems. Water needs to travel through them at high velocity to blow any trapped air bubbles completely through the tube. This is nearly impossible to do without leaving a 1” drain in the overflow completely open due to the pressure differential generated by water waiting to go down that drain and water trying to enter the u-tube from inside the tank. If Eshopps had supplied a 3/4” tube instead of a 1”, it probably would flow just as much considering the drain is the bottleneck here, while simultaneously forcing that volume to go through a smaller passage, which would increase velocity through the u-tube and clear bubbles.

In a nutshell, you want to go drilled whenever possible.

 

[Scotty Buttons]

Any suggestions on the amount of overflow flow I’d need for a 29 gallon?

I have a 36 gallon tank and I have a 600 gallon per hour continuous siphon overflow, I run a mag.5. Pump with a couple feet of head loss. my sump can accommodate about 2.5 gallons in a power loss. And the tank only looses 1.5 gallons. I also keep a old style power head hooked to the overflow. It restarts the siphon in a powerloss.

I believe as long as the amount your sump can hold is at least slightly greater then the amount the tank can physically lose thru the overflow, then your good. Additionally get a overflow that is higher GPH then the pump you run. Or get an adjustable return pump.

Good luck!