River tank with water bridge-kinda long

[buddy09]

Hello one and all. Used to frequent this site some time back and got away for a while, but I'm back under a new name. Anyway, to the point. I "discovered" Martin's river tank manifold some time back and tried to replicate it on existing tanks, without tearing them down. I did so by running external pumps and plumbing, intake on one end, return on the other, as in Martin's setup, just all the plumbing outside the tank. Long story shorter, it worked and I loved the concept. Fish seem to like it too and I think it's a more natural feeling for them....Now I will be moving all my tanks and adding a new one to my soon to be completed fish room (in the garage). This will give me the opportunity to do things a bit differently and in essence start from scratch. Here's what I plan to do and I would appreciate any experience you may have with something similar or your assistance in general......I want to join two four foot 75usg tanks together using a waterbridge and run it as a single 8 foot river tank. Pumps and plumbing will be external, under the stand. For those of you not familiar with the waterbridge concept, it's simply a large PVC bridge connecting two (or more) tanks over the rim. The waterbridge is setup in a siphon mode, much like an overflow box to a sump, only in this case the water flows into the first tank, through the tank lengthwise, into the waterbridge siphon, across into the second tank and then to an overflow at the far end to a sump below, where it is pumped back up completing the loop. It's actually much simpler than it may sound. I will be running around 25x turnover, which should make the fish quite happy. Not all of this water will go through the sump. I will be using two separate pumps, a smaller one for the sump return and a larger one to get the circulation up where I want it. Any experience with this type os setup or thoughts in general would be welcome. I've given this a lot of thought and I can't see why it shouldn't work if properly implemented.....but perhaps you will think of things I haven't.

[Diana]

I have set up water bridges, but not with that much water flow. Might the fish all end up in the downstream tank, unable to swim up stream against that strong a flow?

[buddy09]

Hello Diana. Shouldn't be a problem for the fish. I will likely be using 4 inch/200mm pipe for the bridge. That will slow the flow way down. The fish should have no trouble swimming upstream or down to whichever thank they wish. I may even use twin 3 inch/150mm pipes, further reducing flow velocity, just as backup in the event that something, heaven knows what, went wrong with one, the other could still handle the pumps with no interuption of flow.

[buddy09]

OK, just ran some quick calculations...Forget the twin 3 inch pipes, that is actually less area than a single 4 inch line...Using a single 4 inch pipe approximately 4 feet total length should carry about 2.6 gallons at a time, more or less if my geometry is correct. At a flow rate of 4000gph that's roughly 1.1 gallon per second from the pumps. This should equate to a flow velocity of ...again roughly, I'm not an engineer, 2 feet per second through a 4 inch pipe. Any self respecting loach or catfish should be able to swim upstream against that current easily, at least for the 4 feet necessary to make the transit from one tank to the other....Please feel free to question my thinking or calculations. This is new territory for me and I may have my head up...well you know!!

[sorce]

I appreciate the plumbing outside. I don't like to see anything unnatural in my tank either. After reading the river tank articles, I thought about that too. I was worried about water "outside" the tank, as I live on the third floor.

I work on commercial boilers and I might recommend finding a site in that field to research some flow rates, pipe types, and things.

I can't see the whole picture, but it sounds possible if something gets clogged or quits working, you may overflow the first tank. But it's only in the garage right?

Seriously I love the idea, and will require some pics when its set-up.

Good luck ,

Sorce

[Diana]

The only problem I had with my water bridge was when I did a water change and dropped the level too low. Then I was right on hand to fix it; no problem.

As long as the bridge is soundly made there ought to be no problem. If it leaks or breaks this would be bad.

Sort of fun doing a water change, too. Did not matter which tank I took the water out of or added the new water to, it equalized and the tanks drained and filled at the same time.

[Martin Thoene]

Any design you can come up with that moves the water in one direction as much as is possible will benefit Hillstream Loaches and many other Loaches too. You'll get more natural behaviour from them.

My whole idea with the River-Tank manifold was to keep with the KISS principle. I've had setups with masses of external tubing to move water from A to B and every single join or junction in the pipework is a potential flood.....one reason all my cannister power-filters have stainless steel hose clips on the hose joints.

A water bridge is a great idea, but my fear would be anything that might cause air ingestion causing a syphon break. Personally, if I was going to give that a try I would have two separate water bridges, each capable of easily flowing the pump's output. That will give you a fail-safe at least. Either that, or a float-switch that would cut the pump's electrical supply if the first tank's level got too high.

There's plenty of ways to skin this cat, the River-Tank manifold is just one way that minimizes liquid disasters.

Martin.

[buddy09]

Thanks for the feedback folks, I do appreciate it. As to flow rates, a 4 inch pipe is rated to carry 10,000gph more or less, and I will be using less than a fourth of that I think, so it should be more than adequate. Also, a 4 inch pipe should be essentially clog proof. Even a full grown clown loach or large pleco should be able to swim thru that without having a tight fit. All plumbing will be PVC, all joints glued. Unless I screw up the glue job it should last 20 years or so, long after I've departed this world. As to breakage, that stuff is pretty tuff. Unless I take a hammer to it, again it should outlast me!! ...Martin, I too am flood phobic, which is why I'm going to use an overflow box with a large sump and both pumps will be submersable and rest in the sump, so in the event they leak a bit...and pumps are known to do that sometimes, no harm done and I won't even notice it. The ends of the bridge will be well below the water line, probably in the lower half of the tanks, well away from surface air. I will be using clear PVC for the horizontal section, so if any air does begin to accumulate I will be able to see it long before I lose siphon. Since I'll use a sump the water level in the tanks will remain constant , one of the niceties of going that route. I can do water changes via the sump also, again maintaining tank levels pretty much constant. In the event of a power outage, or when I deliberately shut down the pumps, only a few gallons of water will drain back into the sump from my overflow and no danger of flooding if set up correctly. About the only potential way for this to flood would be if my overflow box clogs up and I pump my sump dry into the tanks. To help prevent this I'm going with an over-size, dual drain overflow, rated at 600gph for each drain and I expect to push only about 700gph thru it, so there is considerable margin. The primary pump will be hard plumbed separate from the overflow and sump return.......I have tried to think of everything, although I probably haven't, which is why throwing the ideas out for discussion is useful.... I spent a few months "hanging out" in one of the salt water reef forums. Those folks do some incredable things with pumps, sumps and plumbing, so they're pretty much the gurus on this stuff. I asked a lot of questions and learned a lot from them, so now I think I'm ready to give it a try.......I'll post pictures as I go and let you guys know how this works out. If I get it right, it should be pretty cool, for both me and the fish:)

[Diana]

Are the tanks drilled or are you using an 'over the edge' overflow?

[buddy09]

Hello Diana. Nope tanks aren't drilled, going over the top with everything. Drilling would be cleaner looking and reef guys do it without a thought. Some of those tanks look like swiss cheese by the time they're done. I've read the "how-to" on it, but even tho I'm a pretty handy guy, cutting holes in a brand new GLASS tank kinda scares me, so I'm gonna whimp out.

[Diana]

I am right on the edge of that, too. I have enlarged a hole in a bargain tank, but have not started from scratch. I am thinking of starting on a smaller tank, and working up. 10 gallon tanks can be found for about $10, so it is not much if it breaks.
What style of overflow will you be using?

[buddy09]

Good Morning Diana, happy Monday. Yeah, drilling seems simple enough if you follow the correct procedure, but I haven't been able to talk myself into risking a tank to try it!! LOL....As to overflow boxes, lots of different ones out there at different price and quality levels. I spent a lot of time on a reef site gathering info. Long story shorter, I'm going with a dual overflow from Lifereef. Every comment I read on them was 100% positive, no problems at all. They are the most expensive, but at least in this case, you get what you pay for. A single drain 600gph box is about $120. The dual that I'm going to use is $200. You can go much cheaper with other brands. I cut corners wherever I can to save money in the hobby, but on some things I believe you have to bite the bullet and go for quality hardware. To me this is one of those areas.....I'll sleep better not worrying about it:)