Overflow problems, (I hate undrilled tanks!)

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zuzecawi

Aquarium Advice Freak
Joined
Feb 14, 2005
Messages
272
Location
Salem, OR
Okay, so I got this really good deal on this 55 gal reef tank... but it's not drilled. I only have worked with built in overflows, and this hang on the back stuff is giving me heart attacks. I've already overflowed it twice, and I just can't figure it out. I got a (quickly purchased) small (145gph) powerhead sucking air from the cpr overflow box (which I swear is wayyy too small) and there's a mag 7 return pump with ball valve. I swear mag 7 is WAAY too much, but when I looked at the tank before, it ran better than it is in my house. I'm retarded with hang on the back, what can I say. And how the heck does an AquaC Remora work? Is there supposed to be a airstone somewhere on it? I gotta say, it's quieter than my Oceanic, even with the durso standpipe, but I just can't take this overflow business. Anybody have any hints why the thing isn't sucking enough in the overflow? Too small a powerhead on it? What's the principle behind this anyways? I swear, by next month, this tank is going on Ebay.
 
I would recommend a www.LIFEREEF.com overflow box. No powerheads to deal with and they're rated at about 700 GPH which will match you mag 7 perfectly. Powerheads and overflow boxs lead to potential overflow accidents.

The remora uses a spray jet that sucks in ambient air from the jet compartement so it's not a true venturi and requires no airstone.

Ryan
 
The aquac remora has no airstone. It uses a spay jet as ryan describes. It works best with either a maixijet 1200 or a mag3.

Look at the side of the overflow and see how much air is collecting at the top of the C channel. If there is air being collected the effecency of the overflow is greatly decreased. Its quite possible the powerhead you have to pull air out is not big enough to cause enough suction on the overflow to keep the c channel free of air. I have a maxijet 1200 on my cpr overflow.

I agree with ryan that the overflows at lifereef are very quality products. I have their double overflow myself. I always liked the U tube overflows more than the c channel overflows. The benifit of the U tubes is they dont require the powerhead to keep air from building up.

What is the head pressure on your tank? The mag7 will only push 400-450gph at 3-4' head. I would say that you would be better suited with a mag 9.5 on a 55 gal tank than the mag7.
 
There is NO way I'd put a mag 9.5 on right now. Not with this overflow. The mag 7 is cranked almost off through the ball valve, I've got a hairbreath between overflowing and smooth flowing. I can't see any air in the c-channel, but I'm a little farsighted and I can't really get a good gander on it. I'm really thinking just selling the tank and keeping the coral for my other tank is going to be the answer here. The gal had crap for live rock, her main filtration was the aquaC Remora and a carbon filter. I'm not real hot on the carbon filter, it makes the water nice and clear, but then, the water is nice and clear on my Oceanic and all I have on that is a SeaSystems 100 venturi skimmer, dsb and tons of live rock. Not to mention I just really don't like the 55. It looks funny to me, after having the 58 for so long, all long but super thin. I've been thinking of liquidating it for a 100 or more Oceanic, maybe even letting go of my beloved 58 in the cause of a bigger tank. (Decision to be made AFTER said tank is here, of course.) In the meantime though, I'd like the overflow to work without killing me through anxiety. So I'll check out that lifereef. I do have a maxijet 1200 on the remora.
Any other helpful hints? Thanks for those you guys have already posted.
 
The overflow should have a model number on it. If its accessable to read this look up the model number on CPR's website. If there is no air in the c chamber and you have to have the mag 7 throttled all the way back the overflow itself is way undersized to move the capacity water needed.

This is a used tank and if so was the overflow and pump setup included or is that something you picked up after the fact?
 
This is a twice recycled tank. The lady bought it used, and I bought it used from her. It had all the filtration stuff sold with it. And it's more than likely way undersized. The sump she built, out of glass and a TON of silicone. And I think she got all the equipment used with it. I'm not sure though, she may have added some of it.
 
Hmm.. opening that up to read now. I did today, scrub the *#%! out of the overflow box, and the little screen thingy on the actual overflow tube. That seemed to help a LOT, but it still is just cranky, and overnight due to evaporation my pump just about gave up the ghost. I got up this morning to find just enough water in the sump to keep the pump wet. Scary. Super scay. I'm really looking forward to getting rid of this thing. Right now I'm just trying to get my chemistries between tanks closer to matching so that I can transfer the corals to my oceanic. And those poor fish! I'll post pics later of the sorry shape that yellow tang is in.
 
I have read this whole thread. It really looks like you are pretty unfamiliar with some of the basics of hob overflows. 1st you should not be afraid of overflowing the sump. I don't see in your post any specifics other than you have a CPR C type overflow nor how large (capacity) the sump is. Thats the 1st thing I would rid myself of were I you. As mentioned aleady U tubes are the way to go if your using an hob overflow. They are a pain to get started but *if* you have them setup proper when the sump pump cycles off, the back flow from the tank fills the sump roughly 3/4 of the way and then your siphon break holes (You do have those, right?) stop the back flow (reverse siphon) into your sump. When the pump comes on the U tubes restart due to a little physics magic. Long story short, the C style overflow you have calls for some sort of device to keep the air from preventing it from working. I have no experience with these overflows and they may be a great product, but I wouldn't trust anything that requires a device to keep the air out of them. Just my opinion.
You mentioned a couple of things that should not be happening if the over flow is close to your pump in its capacity. (GPH) Your Mag 7 is capable of 700GPH which at 4' (average head height for most tanks on a stand with the sump underneath) you have the potential to push 480GPH with the pump wide open. The smallest CPR Overflow box (C Style) is rated at 300 GPH. You mentioned that your had the pump throttled way back. This doesn't add up. So, now I am caught up with you in that, something is wrong. First, we need some details on your setup. Folks have already asked you to post the model of overflow..Important. We also need to know how it is setup. In lieu of that I will describe briefly how it should be setup..Pretty simple really..The overflow should (obviously) be plumbed into the sump. *Do not* place any valves or other means of restricting flow on this run. You control flow by a valve on your return line *only*. You *can* place something on the inlet for making disassembly easier, but never restrict flow using the inlet tube..it paves the way to new carpet and empty tanks. Ok, from the sump there shoud be a return pump (Your Mag 7) This return line (Should be 1/2") will have a ball valve in line with it. This is and only this is what you will use to 'throttle' the return pump to match your overflow.The return line will then lead on up the tank and into either a pvc type end or whatever nozzle. About 1/2" beneath the waters surface there should be a small hole drilled in to each return pipe. This is the magic that breaks reverse siphon should the power go out. Once the power is cut from the sump pump (And you can test this, just unplug the pump) your return will start to back siphon into your sump. (*hint* don't run your sump normally full to the top. Leave enough room in it to handle your power out back flow..Makes for dryer days and nights..) When the water level reaches the hole in the return line it will gurgle and then the siphon will break. When this happens, your tank overflow *should* (U tubes do..) stay 'primed'. That is, the water in the overflows inside box and outside will reach equilibrium and the water should stay in the 'C tube'. Now the fun part..When power is restored to the sump pump, the overflow starts again and like magic, the system flows as if nothing ever happend. *Points to remember*...Siphon *can* break on any overflow thus causing the sump pump to pump out all the water from the sump and overflowing your tank. Its rare but I have seen posts at this site. At any rate thats the short version of how all this should work. You need to check what the model overflow you are using is rated at. If you believe you are not achieving the approx 300GPH (assuming the smallest CPR C style I can find) then do check your inlet tube from the tank to the sump to make sure no trash or critters are in there. I had a crab once upon a time that loved to ride the line into the sump. Problem was he never made it past the inlet on the overflow and caused a drop in the overflows efficiency. The rule of thumb is to try and use an overflow that will outpace your pump. That way if for some reason your pump gets adjusted wrong you won't have to worry about over driving your over flow and then overflowing your tank.
I have used a U tube style over flow for almost 2 years and while I hav come close, I have never overflowed the tank. In the early days (due to not understanding the physics of the overflow) I did make some mistakes that caused me constant grief with the water levels. Once you get the hang of it and get the 'kinks' worked out it should work like a champ.

BTW, a 55G tank with 300GPH turn over is only about 5.4/5.5 times per hour. I am not saying its bad, but consider shooting for 12 - 15 times per hour if you decide to purchase new equipment.
Ok, theres my advice for the day!

Peace.
 
I have to start this by thanking the people who've given me helpful advice. And to reply to this last lengthy post:
Okay... first... I'm not worried about overflowing the sump. If that was the impression people are getting, rest assured, that's not the problem. The problem is the stupid overflow box can't keep up with the return pump. Now that we got that out of the way...
The overflow box is a CPR model CS50. There are no ball valves on the inlet, and I don't know how anybody could get the idea from these posts that there is. As I said previously, I cleaned the inlet filter as best as possible and it has improved flow. The inlet hose has no obstructions. The return pump has a ball valve. It is cranked nearly shut. After cleaning inlet and filterbox I opened it some more but it still tries to overflow the tank. I do not plan on keeping this aquarium, it does not please me, and I don't want to sink money in a set up that I don't enjoy. I bought it mainly for the corals that came in it, I tried to buy only the livestock but the woman would only sell the whole set up. The sump is of unknown capacity, as I said in previous posts, the woman made it herself with lots of glass and silicone. Obviously, it being a standard 55, the sump is very small. Small enough to get in and out of a standard 55 stand. So I'd say less than ten gallons. And I'm not a complete newbie, I have been experienced with sumps and their principles, I have had several drilled tanks, and I do know better than to overfill the capacity for the event of electrical failure. The tank does hold siphon in case of shut off, but only with the use of the airlifter (I had a powerhead but it sucked so now it's got an old airlifter I had lying around). As far as I can read, the airlifter is the ONLY way to preserve siphon with a cpr overflow/prefilter box. I appreciate helpful posts, and I HAVE been the first to admit that I have NO experience with this HOB crap. I can't help but bristle a little though at the implication that I'm a complete idiot which I get from this last post. I don't think it's unreasonable to post to here asking for help from other people with more experience with certain types of filtration equipment, in the sake of saving my floor from innundation. I also don't feel that admitting to inexperience with one form is admitting to incompetence with all forms. Furthermore, I do think that experience doesn't make excuse for lack of tact. Often on this forum I see people get overly excited and jump down other people's throats for simple mistakes, sometimes with ample justification, but sometimes in no more sense than that of any mobbing. I don't necessarily think that PC here is trying to come off as arrogant and condescending, but none the less, as the person who's asking for assistance, I can say that's how it sounds to me. I'm willing to be wrong here too, maybe it's just been a long night of fiddling with this dang thing and getting no real results, and maybe I'm feeling a little like an idiot myself for the impulse buy.
 
I use a CPR CS90 overflow. It works great but the trick is to use a large power head. I use a Maxi-jet 1200. Also having this- http://www.premiumaquatics.com/Merc...OD&Product_Code=MJ-VENT&Category_Code=Maxijet -will help. Having the venturi on the intake, as opposed to the kits that go on the output of the pump, allows it to work much better. I have tested my CPR atleast a dozens times and using the set up I described it has not failed once. Hope that helps.
 
Sweet tip MT, I can feel pretty cheap and happy trying this out. I've got a few odd maxi 1200's lying around, this will help. I went to that cpr site nsu7 posted, that was very helpful, I changed from the powerhead to the air lifter and that seems to be keeping the flow up some, but it's still just a hairs breadth from overflowing. Anything at this point is worth a try.
 
I have posted a few times at cpraquatics.com. They have some ownership or collaboration w/ the manufacturers of the aqua-lifter pump AFAIK. That's why they "push it" so hard. I read many threads on lots of different forums before I bought the CPR overflow and most of the time if there was a problem there was a common factor-the aqualifter pump. It's just not powerful enough. The people who use Rio 600(?) or MJ 1200 had good results(I would avoid the Rio for other reasons though). Another good thing is you can hide the ph in the sump and just run an airline up to the overflow. FWIW I can run my Mag 9.5(950 gph) wide open w/ the CS90(600 gph). The only problem is the flow is too much for my sump and bubble traps. Micro-bubbles end up getting back to the display tank. IMO the MJ 1200 w/ the intake venturi fits the CPR overflows PERFECTLY! I have just a few small bubbles in the "C" of the overflow at any given time. Keep in mind that any bends or curves in the overflow tube/plumbing will cause restriction. Good luck.
 
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