Marineland JetStream - Overflow Control rod - how works?

[mound]

Hi - I've recently setup a 125g Marineland JetStream system - with the dual input/output tubes. (i'm still in the setup phase, trying to get the sump/jetstream working properly)

They use a "overflow control rod" which is just a length of hollow tubing that goes up or down into the tube which the water overflows into. Raising or lowering it will change the GPH and change the water level. I can't seem to get the overflow to stop gurgling, and am a loss for just how this overflow control rod works? Could somebody please explain?

The tubing I believe, is the control to stop the gurgling....you run it down the tube until you here it decrease the gurgle noise and then secure it...
It works in the same way as the vents on your plumbing in the house..you know, the pipes sticking out of the roof? This allows the water to get air as it flows down the tube and thus, reducing the gurgle. It takes time to get it just right, but, this hobby is all about patience...

[mound]

I guess that makes sense. I don't understand how that will affect water level though. The water will overflow at the height it first can.. I'll have to play around some more and try and see the effects.

[blhigbee]

why have an overflow? if the tank is set up to one level of water then how can it possibly overflow? or is there something im missing.

[mound]

it's a drilled tank, with tubes running to the top of the tank connected to bulkheads at the bottom. There are 4 tubes, two outermost are where the water overflows, the two inner is where it's pumped back up through from the sump. Perhaps this will better explain:
http://www.marineland.com/products/c...on_jssuper.asp

Now if the water level reaches the level at which it will pour over the overflow tube, I don't see how having a thin air tube inserted down the middle of it can possibly allow the water level to rise above the opening into which it overflows.

I'm sure it's me that's missing somethign.

I don't see how having a thin air tube inserted down the middle of it can possibly allow the water level to rise above the opening into which it overflows.

It doesn't. It just allows air flow down the tube. The same amount of volume is going to go down the tube, it just keeps it from backing up to the point it rushes back down, thus causing the burping or gurgling...

blhigbee wrote:
why have an overflow? if the tank is set up to one level of water then how can it possibly overflow? or is there something im missing.

The purpose of an overflow is to implement a sump or refugium into your system. It allows water to flow from the main tank, down a tube or pipe, to the sump/refug, and then a return pump sends it back to the tank. It has a J-Tube or U-tube which sits over the tank in each part of the OF that is submerged on each end so that when the power goes out, you do not lose prime. when the pump starts back up, the siphon stays and water flows again.

If you do not have a sump or refugium, there will be no need for an overflow...

[mound]

It doesn't. It just allows air flow down the tube. The same amount of volume is going to go down the tube, it just keeps it from backing up to the point it rushes back down, thus causing the burping or gurgling...

Ok that makes sense. I guess it's the way the documentation is worded -it states that raising or lowering the tube will reduce/increase (or vice versa, don't have it in front of me) the GPH, as well as raise/lower the water level. so as long as my primary concern is to adjust that to elliminate the gurgle, I think I'll be OK..

On a related note - not sure if you've seen these Marineland JetStream systems or not - on the 125g tank there are two inputs and two outputs. Because I messed up the water level on the right side of the tank is 1/8" lower than on the left side. (blame it on the guy who built my house.. I never checked for level though)

Since there's an overflow on each side -and they are exactly the same height - I'm getting more water flowing over the left side, which keeps the water from "fully" reaching the overflow on the right side (though it does flow over, just not at the rate as the left.. we're only talking 1/8" here..)

I'm wondering 1) how much does this matter? so I'm drawing more from the left side of the tank than the right - it's getting pumped back up equally to both sides.. 2) assuming it does matter, I guess I can try to shimmy the left side up 1/8" to level it out and since the tank hasn't even been cycled yet, I could empty it.. hmmm..

[reefrunner69]

From the pics it looks like there is a cap on thie overflow, and the rod actually closes the cap some, that is why it will raise and lower the level in the tank. IMO, it is a better method to adjust the amount of water flowing to the tank to adjust the level/flow. The reason one side is higher than the other, is because the tank is either not level, or there is resistance in oe of the overflows.

[reefrunner69]

LOL, sorry, should have read the entire post, instead of spot reading it. !/8" isn't too bad, but over time, it will put enough stress on the seams to cause a leak. How much time....???? Could be next week, could be 15 years, depends on how quality control was working the day they made your tank. If it was me...I would drain the tank and level it.

[mound]

well I've leveled the tank out (some composite shim wedges, and a hammer, got 'em under and raised the left side a whole 1/4" w/o emptying it..)

anyway - I'm still having problems setting this thing.. either the sump fills up and nothing seems to overflow, or the sump empties, and it gurgles.. somewhere a happy medium!! (I hope!)

[mound]

From the pics it looks like there is a cap on thie overflow, and the rod actually closes the cap some, that is why it will raise and lower the level in the tank

Correct - now this confused me further - recall there is an overflow tube on each end of the tank - could it be that I could set, via the overflow control rod, the overflow level on each end of the tank seperately?? like I said, I have corrected the level problem - the tank is perfectly level now, but with their control rods set differently, the water reaches up to a different level on the overflow tube cap..

weird.. I'm probably rambling, just trying to figure out this new system, it's my first experience with an overflow/sump mechanism, and the "JetStream System" doesnt seem to have much info on the net about it, user testimonials etc..

[reefrunner69]

I would use the bar and open them up, full tilt and then make very small adjustments until it is where you want them.

[mound]

shortly before I read your reply I did just that - I pulled each tube all the way up, and there was no gurgle.. now I'm sloooowly pusing them back in. ... if the overflow control rod is meant to elliminate gurgle - why is it that the gurgling is actually coming from the control rod??

[reefrunner69]

I don't think it is meant to control the gurggle, from the pics I saw on the website you linked, the rod looked solid. For it to eliminate the gurggle, it would have to be hollow.

[mound]

the rod is hallow. with a tension ring to set how far into the main flow tube it extends. when it's "too far" , I get gurgling up through the hallow tube.

[reefrunner69]

There is an old trick to quieting an overflow. You stick a piece of airline tubing into the drainline, until it quiets down. I've never continued to put more tubing down in it, so I suppose if it was "too" far, it might become noisy again.

[mound]

yeah - that'd be essentially the same thing here.. and another thing I notice about this "control rod" - there's a "flare tip" at the end of it that's down the tube - like a tension clip, only it flares out (picture like, a pair of bell-bottom jeans) and you can see when the water drops down the tube, it "flares out" as it passes over this flared end - perhaps the space consumed by the flared water is what creates the increase/decrease in water flow down the tube. I think you're right - too far up and too far down will gurgle.. I think my mistake was assuming that the starting point in setting it up was all the way down - starting all the way opened up seems to be working better.. When I find the happy medium, I guess I'll just place the tension ring accordingly to keep it in place, and ship off the extra portion of the tube that sticks out the top (otherwise I can't put my glass cover in place)..