HOB OVerflow

[kcfehring]

I have a 44 gallon corner tank with a biowheel filter that I would like to upgrade with a sump/refugium. I know that the best way would be to cut a whold in my tank and do it that way, but I am not sure if it is glass or acrylic and don't want to chance it. So the overflow is my best bet. Now I am new to reefkeeping and while I do know a few things it is usually just enough to get me into trouble! LOL I think I have decided on a U - shaped overflow but I don't know what brand would be best and I am still confused about how to get the water from my sump back to my tank. I am thinking of purchasing a mag drive pump for my sump that is rated for 700 gph.

Any and all help is appreciated!

[lcstorc]

I really know nothing about HOB overflows, but the pump you use on the return is going to be determined by the rate on the overflow you get. You don't want a pump that pumps more water than the overflow is rated for or you will cause a flood. Also when buying the pump you want to account for head loss in you final calculations. As to how you get the water back from the sump, the answer is with the pump pushing water up through a return line. Since the tank is not drilled you are going to need a pvc pipe and fittings to take the water from your sump and over the wall into the tank.

[BigAl07]

I can't really lend any help in the technical part but I can tell you that's a GREAT idea. Adding a refugium to my tank was the SINGLE best improvement I made to my small tank. You're doing the right thing. You may encounter some additional hurdles due to it being a corner tank but the end product will be WELL worth the efforts.

Take note that pumping the water UP from your sump will greatly diminish the actual flow of the pump but I think that one will be more than adequate for what you're wanting. You don't want a LOT of flow through your sump/fuge area.

Good luck and happy surfing!

Allen

[michael_cb_125]

I have two CPR overflows. They work great. But as Lynn said, make shure that the pump and overflow are rated for the same GPH.
Continuous Siphon Overflow
Many website will tell you the head loss that each pump will recieve, make shure to take this into consideration.

[kcfehring]

So, if I am undersstanding this right the pump is actually only for the return. The overflow runs on gravity?

I am thinking of buying a life reef HOB overflow which is rated for 700 gph, the pump I am looking at is a mag drive MD7 with has a rating of 700gph with a max head of 12 ft, but it doesn't say anything about head loss. How do I figure this out?

Also, if I have a pump with 700gph, a hydor korilia 1 with 400 gph and a penguin 980 with 230 gph. Is that good enough turn over for a 44 gallon tank?

Thanks

[kcfehring]

Originally Posted by BigAl07

I can't really lend any help in the technical part but I can tell you that's a GREAT idea. Adding a refugium to my tank was the SINGLE best improvement I made to my small tank. You're doing the right thing. You may encounter some additional hurdles due to it being a corner tank but the end product will be WELL worth the efforts.

Take note that pumping the water UP from your sump will greatly diminish the actual flow of the pump but I think that one will be more than adequate for what you're wanting. You don't want a LOT of flow through your sump/fuge area.

Good luck and happy surfing!

Allen

[michael_cb_125]

You are right, the pump is for the return. but depending on which overflow you choose, you may need a lifter pump. The CPR needs one, but I am not sure about the model you are looking at.
As for the turnover on your 44 gallon, if you have both of those pumps on the tank you should be ok. Just remember that the more times you turn over your water the better. I have a 100 gallon tank with 1200 gph return from my sump. I also have two 600 gph powerheads, and a rufugium that is putting in 300 gph. So technically I am turning my tank over 27 times/hour. With the two pump you have you are at about 14, which should be fine .

[Disciple882542]

you don't have to worry about matching the pump to the overflow. I would get one comparable simply due to heat and energy usage...but it's not necessary to exactly match the output of the pump to the overflow. Simply plumb a ball valve on the return line between the pump and the tank. That way you can adjust how much water goes back to the tank.

God bless,
Disciple

[rDr4g0n]

yeah like disciple said, get the pump and overflow in the same ballpark, then fine tune with a ballvalve. i use a continuous siphon overflow and it works great. most people say its more prone to failure than a u-tube, but they both work on the same principle and are both prone to the same sort of failure (mainly airbubbles building up and breaking the siphon, or air leak of some sort).

anyways, your overflow can only overflow as much water as your pump is returning. in other words, you pump sets the pace. the only trick is to make sure that the overflow can keep up with the pump.

and yes the overflow uses gravity (through siphon) so you just need to be sure to get a decent return pump, and thats about it. heres a schematic of my setup to give you an idea of how it works...


and my return pump with ball valve

[MR PALM BEACH]

If you dont have a large enough pump your sump will not be able to keep up with the overflow. Meaning there will be more flow going Into the sump than returned. I had 29g with an HOB overflow, the return pump was a RIO3100 (900gph) between the head feet It probably broke down to 700gph. I put a spare RIO 1400(400gph) In place of It just to see the difference and the overflow overpowered It and filled the sump quicker than the water could be returned.

This Is the HOB I used.

[Scouter Steve]

Originally Posted by MR PALM BEACH

If you dont have a large enough pump your sump will not be able to keep up with the overflow. Meaning there will be more flow going Into the sump than returned. I had 29g with an HOB overflow, the return pump was a RIO3100 (900gph) between the head feet It probably broke down to 700gph. I put a spare RIO 1400(400gph) In place of It just to see the difference and the overflow overpowered It and filled the sump quicker than the water could be returned.

This Is the HOB I used.

Your overflow can only drain so far, then it has to wait for water pumped up from sump. Therefore the pump does control how much flow not the overflow controlling how big a pump. Your sump does have to be sized properly to allow this to work right.

[rDr4g0n]

Originally Posted by Scouter Steve

Your overflow can only drain so far, then it has to wait for water pumped up from sump. Therefore the pump does control how much flow not the overflow controlling how big a pump. Your sump does have to be sized properly to allow this to work right.

ya i was gonna say that but i couldnt get it into 2 sentences or less lol

[BoomerD]

First of all, Lifereef makes the best overflows on the market, hands-down. I've used them on & off for nearly 15 years, and have never seen one fail to restart, nor have I even heard of one failing to restart after a power outage. They're more expensive than the others, but IMO, they're worth it...(how much does it cost to replace flooring after your tank floods?)

Next, your overflow should not be able to drain faster than the pump can return. Once you have things set properly, the overflow should only drain as much as the return pump sends back to the tank. (Yes, if you have an overflow with a 1-1/2" bulkhead, it may drain faster than a Mag 5 can keep up with, (at first) but if your sump is set up properly, that won't be an issue.

From Lifereef's site:

"Contrary to what you have heard or been told you do not have to match a prefilter box with the pumps output volume. The prefilter will handle from a zero flow to its maximum flow rate. That is why we only make two models of boxes: single (up to 700 gph) and a double (up to 1400 gph).

Siphon tube prefilter boxes are preferable and SAFER to use than siphon tube-less boxes for several reasons. They are easier to clean, easier to maintain, easy to start, and do not require faulty check valves or unreliable secondary powerheads to remove bubbles and air from the tube. If the powerhead fails your tank overflows! To clean a siphon tube operated box just remove it from the prefilter and clean, no need to remove the entire prefilter box.

The water velocity through a siphon tube is faster than the water velocity through a tubeless design and therefore any bubbles generated get sucked right through a siphon tube. Bubbles build up in the tubeless designs, that is why they have powerheads to hopefully keep them operating!

The inner slotted prefilter/skimmer box can be adjusted vertically to set your aquarium water level. This slotted box engages in a vertical track that keeps it from being knocked out of alignment. A large 1/4" diameter fiber-reinforced screw and nylon wingnut attach the inner box to the outer box.

Once started the siphon will always RESTART and resume flowing water after a power failure or when you turn the pump back on. There is no need to restart the siphon tube."

[rDr4g0n]

i just want to add in defense of weir style overflows that i have been through multiple power outages and mine restarts everytime. i dont even have a powerhead sucking air bubbles out of it. once a week or so, i just suck out the air bubbles (they taste like fine cheese). they are more compact and have a smaller footprint on your tank. they use to same principle to restart a siphon when the power goes out, or when the water level drops below the skimmer box level as the u-tube boxes.

they are harder to clean though, and air does build up in them. but i feel these cons arent as bad as people often make them out to be.

[Triggerjay]

I have a CPR-100 700gph overflow, with an aqualifter pump to keep air out of the thing. I have not had any issues with it YET, but it will need a cleaning soon, and the whole box will have to be removed. so in that aspect, its gonna be a pain.,.

Jason