Please Educate me on HOB overflows

[mnestroy]

Background: I am attempting to build a sump for my 40 Gallon Breeder. I have a 20L which I will use for my sump.

I have a Remora Pro HOB that I will put on the side of the sump. and a Eheim 1262 Pump (900GPH)

My understanding of overflows is very limited, so please help me purchase the right one... (and correct me if bigger isnt better)..

It is my understanding that an HOB Overflow can only drain as much water the return pump can put into the tank? So would it hurt if I purchase a high rated overflow like the CPR CS102 with (two 1" drains, rated at 1400GPH)??

If my pump is gona return lets say 700GPH (after head loss etc) will the CS102 overflow be a problem?

1. Will it make more noise than if i get a smaller unit?

Thanks

 

[jessp]

i think if your over flow is running 1400 gph you will lose siphon on the overflow because the tank wont' over flow enough water. over flow will always be empty

 

[Ryanqk]

Yeah you will probably need a weaker pump model for your return, honestly i have a very nice system working for me, i have a siphon overflow box i got from my LFS (i dont know if its a rated model or something the guy built himself) on my 30gl draining to a 10gl fuge below, and my return is a maxijet 900, thats about what mine handles although i may be able to use a 1200 if i can sort out some issues with the U tube.

 

[sjm817]

Yes, an overflow only drains back what is pumped in. For that setup, you dont need a 1400 GPH overflow. The CPR overflows are very unreliable. They cant maintain a siphon on their own and require a vacuum pump for operation. There are multiple ways it can fail. I would highly recommend the 700 GPH Lifereef overflow for that setup. They are the best, most reliable HOB overflows in the industry.

That 1262 is WAY too big a pump for that setup. Even a 1260 would be too big. I would use a 1250.

 

[mnestroy]

How is the eheim 1262 way to big?

After I put some adapters and throw in distance, i'll prob be around 600, and I can also split the return and redirect some flow back into sump.

So hopefuly even though you say my Ehein 1262 is to powerful, I can make it work...

Also what makes that other overflow better than a CPR? I've heard nothing but positive things about the CPR

 

[artnsx]

air bubbles are a problem with the CPR. you end up having to buy either an aqualifter pump or hooking it up to a powerhead....annoying and a waste of time. I had a CPR and regret ever getting it, got rid of it after 2 weeks. Spent hours on CPR technical support boards online.....everyone has similar problems and the help they offer isnt that great.

 

[sjm817]

People have used a 1262 in a 120 and regretted it. Too much flow through the sump. Noise, microbubbles and the sump not having the needed reserve capacity are some of the problems you will have. That pump has almost 800 GPH @ 4' (measured).

Where have you heard positive things about the CPR? Do a search on this message board. The Lifereef is better because it is the most reliable overflow you can buy. It always maintains siphon and does so without the need of something you have to plug in. Its also a heck of a lot easier to clean.

 

[Shagsbeard]

I've found my CPR overflow to be fine. I've had it working for a couple weeks, and perhaps I've been too distracted by other things to notice there's a problem. Go figure. The concern I have here is the 20L sump... that's only about 5 gallons. If you pump only 200 gal/hour through it you're talking 40x flow. That's got to cause lots of air bubbles in suspension.

I'd be interested in a PM detailing what are these many things that could go wrong with my CPR. The power lifter will establish siphon, as well as maintain it... the others need to be manually started every time siphon is broken. There is no siphon system that "always maintains siphon". Cut off water supply from it and it's going to lose it. I agree though that most siphon systems are virtually fool proof.

 

[sjm817]

No need for PM, I can post it here
1) aqualifer pump fails
2) air leak in tubing
3) tubing clogs
4) air nipple clogs.

The air nipple clog happened to me twice in 3 months. All it takes is a tiny speck of anything to clog it. Numerous people have had this same failure. Lifereef needs nothing external to keep it running problem free.

There is no siphon system that "always maintains siphon". Cut off water supply from it and it's going to lose it

Not true. A siphon should never fail. The only way for that to happen is to introduce enough air into the siphon tube to break it. That is the problem with a CPR. It cant keep the C Channel clear of accumulated air without the use of an external pump.

 

[mnestroy]

Sigh, okay I am totaly confused and frustrated then..

I can return the Ehiem 1262... I know its pretty powerful, but I had wanted to buy a pump that I could later use in a larger sump... For now what is a good pump?? the 1250? thats only rated at 317GPH isn't that kinda low?

Okay maybe not the CPR who sells this other brand your talking about?

Best yet, tell me what Model Overflow and what model Return pump would be a good combination for a 40gallon breeder with a 20long sump

 

[jessp]

i hob model that is rated for less gallons per hour.

 

[sjm817]

I didn't intend to frutrate or confuse you. I'd say getting too big a return pump is one of the most common mistakes I see made. The flow between your display and sump as a general rule of thumb should be 3 - 5x display size, or 120 - 200 GPH for a 40G tank. The 1250 would be in that range after headloss. If you really want a bigger pump, you can get a 1260 and put a valve on it to cut back the flow.

Lifereef sells direct. You would want the single model.

 

[HornetMech242]

Every tank is different so you cant give advice for the CPR overflow based on what happened to you. I had mine running for 5 months with the $9 pump and pre filter and it made it through multiple power outages. I do not have a lot of particulates in my water column so I have never had a clogged tube or air nipple. The bottom line is if you maintain it just like all the other aquarium equipment it will give you trouble free service.

In case you are wondering why I got rid of it, it dropped off the truck when I was moving and it cracked so I just threw it away instead of trying to fix it. But I would recommend the overflow with the pump and pre-filer.

Chris

 

[sjm817]

I'm not giving advice solely based on what happened to me. Many people have had the clogged air nipple problem. CPR is aware of the issue. I called tech support about it and their answer was to poke out the clog with a paperclip. :lol: At that time, I was travelling a lot and wasn't available to do the daily checks to see if the overflow was working properly. It isn't so much of a stretch to say a siphon overflow that needs nothing at all besides the laws of physics to maintain a siphon is more reliable than one that relies on an active device. I think the "mine never had a problem" so there is none is not the most accurate way to look at things.

Both Lifereef and CPR earned thier respective product reputations based on user experiences.

 

[mnestroy]

Okay, so i'm clear...

we are all in agreement that the Eheim 1262 would be a bit to much flow for a 40gallon tank with a 20L sump??

Even if I split the return and have some flow coming back into sump?

I obviously do not want bubbles...

So what is a good flow i'm looking for then? 200GPH only?

 

[ek9vboi]

Do this, my set up is somewhat close to what you have. I have a 29g display and a 25g high (uses about 20g max; 5g reserve incase of siphon break).

Are you planning to have a refugium in your sump set up? If so I would follow the 3-5x flow, but it is not necessary to follow it because as long as you do not have microbubbles you will be fine. I have mine built in to my sump.

As of right now I am just some no name HOB overflow, much like the LifeReef. Works great and has NEVER broken siphon, but its pretty loud. I am working on a stockman silencer to quiet it down.

Excuse the wires, its a mess but has been cleaned up!

I am currently using a ViaAqua 1300 (370gph) for a return pump and it seems like it isnt pumping back as much as I wanted. I also have it running to my refugium:

Some more loss with the return pump.

What I am planning to do and will do this week is redo my plumbing and add my new return pump which happens to be an Eheim 1250, it will solely be returning the sump water back into my display tank. As for the refugium it will have a Maxi Jet 900 or 600 pulling water from the return area of the sump into the refugium.

The main point of all this crap I just wrote is to be ENERGY EFFICENT. Remember running a larger pump will cost more and for the returning water to be diverted back to the sump is... well a waste. My current return pump uses about 32 watts. The eheim will be 28watts plus 10watts max for the maxi jet = 38 watts total. In turn I will have a more reliable, QUIET, overall better return pump. Plus I will gain more flow for about 6 watts.

Click the red house to check out my tank, I had to make it happen with the Remora HOB Skimmer as well, this my reason to get a 25g tank. I subscribed to the thread to see what you will be doing. Any questions PM me.

Just remember... you don't want too much flow because it will cause microbubbles to form. Also too much flow will kill the point of a refugium due to the fact that the water moves too quick for the macro plants to absorb nutrients.

 

[sjm817]

1262 would be WAY too much. It is a really strong pump. You would have to send a lot (most) of the flow back to the sump. A 20L is not very big. Its only 12" wide and tall. You wont be able to do much for baffles. A 1262 would make that sump a boiling cauldron. I really think the 1250 would be a good pump. Unfortunately, in an Eheim, there is nothing between the 1250 and 1260. As I posted previously, if you want a bigger pump, the 1260 would be (still too big), but not nearly as bad. To take care of the display flow, use powerheads. The Tunze nanostreams will be out soon. One or two of them would be nice.

 

[mnestroy]

What if

I throw a Squid on after the return, looks like that would reduce the pump by 20%+ would that work? or should i just return it, ehhehe

 

[sjm817]

I had the same thought. The problem is, a 1262 is too good a pump. I put a SCWD on a Mag9.5 and it cut the flow in 1/2. An Eheim stands up to head pressure a lot better. You would still have way too much even with a (guess) 20% reduction in flow.

Maybe a 1260 and a SCWD? That would be closer.

 

[cdentii1]

The Cpr overflow IMOP/IMOE is nothing better than a paper weight and as a added bonus it is a excuse to clean your carpets. As far as the return pump is concerned go for the smaller pump 1250 should be fine, if you want more water circulation I would recommend installing A mag 9.5 thru a SCWD in a closed loop.