cascading waterfall Loach rivertank

[Vancmann]

Ok, I have been making/designing a rivertank for my loaches for the past month. River tanks seem to be getting more popular and my loaches are getting too fat just sitting around and not and not exercising. Here is a not so good drawing of how it looks minus some details like plants, rocks, cascades ect.. I have already done the whole thing using a 120G acrylic tank with acrylic inserts/barriers (to see through and through) and it has been final tested. The flow was also tested using Metylene blue and it takes less than a minute for the blue to travel 10 feet (from pump outlet to pump inlet) . After some scary mistakes it is finally done and it flows from the waterfall quite rapidly. Also, the back section will be cascaded for a steplike flow through and over the filters. As the back is narrow, the flow of water there is quite strong with the use of a 950GPH rated pump at 0 ft head pressure. I might consider a bigger or more auxilary pumps when it is stocked. The whole unit will be enclosed to allow plants to grow under and above water level and I have installed cups along the back wall for this.
I would greatly appreciate any comments and suggestions from anyone with experience with river tanks. Althought is tested without ornaments, fish,... I am not sure what will happen when it is stocked.
Well here is my version and please note, it is not drawn to scale. The real photos will come when I have planted the tank and installed the filters which I am waiting on from the supplier.

[Mark in Vancouver]

Hey. That's pretty cool. I want to see some photographs, though - you've lost me on part of it...

You have a plexi divider down the length of the tank, right? So you're pushing water essentially up to get this effect? I want to know more about the pump you're using, and how you plan to keep the fish out of the intake because that kind of pressure must take a heck of a draw.

I think the concept should be examined more, and I love that you're doing the experiment. I also really like the idea of a length of plexiglass in a tank for hillstream loaches - all the more surface to suck, and possibly more of them out in the open.

Cool idea. Please get some shots if you can. I think we'd all like to see the design working.

[Vancmann]

Hey. That's pretty cool. I want to see some photographs, though - you've lost me on part of it...


You have a plexi divider down the length of the tank, right? So you're pushing water essentially up to get this effect? I want to know more about the pump you're using, and how you plan to keep the fish out of the intake because that kind of pressure must take a heck of a draw.


Cool idea. Please get some shots if you can. I think we'd all like to see the design working.

Yea, I am excited bout it for the loaches, they will have a playground. In the drawing, I skipped quite a few things.
The strainer for the inlet is a cylinder that is 1.5" dia and about 7" in length and perforated with large elongated slits but not big enough to let 2mm gravel through
The plexiglass does run the length of the tank at 80% the height except for the 3.5" wide notch at the draining end which is shaped like this " \__| " to allow waterflow. The notch is about 3" deep.
The Pump is a "model 9.5 mag-drive pump" It is rated to do 950 GPH without headpressure. I anticipate a little head pressure from the difference in water level between sections which would be about a couple inches.

So you're pushing water essentially up to get this effect?

Sort of, but it depends on the height of the "cascade makers". In the test, I was just pumping the water from one tank into another essentially, until the section being pumped into overflowed back into the emptying section. If I were to place high obstacles in the back section (slanted dividers I will use to cascade the water) the pressure would build up as the water rises to flow over these barriers. The higher the barriers, the more the pump will have to push against the increasing pressure of the higher water level. I only have a limited area within the tank to work with.
I will have to explain the whole thing if it goes according to plan when stocked. I guess the final test is not done yet.

[Mark in Vancouver]

You're serious? You can actually produce a difference in depth between the front and back in inches? Now I am very interested. This I have to see.

Have you considered inserting a short piece of plexi horizontally at the outflow point, to further the effect of the waterfall. It might create good effects with turbulence. If you don't have a camera, go and get one before you put fish in there! A bare tank shot would be very useful, I think.

[Vancmann]

Yea, and because of it I had to redo, modify and reinforce the center piece throughout the length. The whole thing broke loose when the difference got to over two inches.
I actually did considered the horizontal piece for the water to spout but I did not want a piece of material projecting out to possibly hurt the loaches. After they are used to the tank, I will definitely do that upgrade. In the mean time, I have an angled piece pointing the flow back towards the pump inlet. Hmmm... But now after thinkinng about again (thanks), I can solve that issue by bending the end back around to form a lip. Back to construction.

[Vancmann]

Here is a front and rear view I just sketched out using Microsoft paint to help some. Again, not to scale. All the cycles of filtration are located closer together and fish only have access to cross over the Bio filter. They will not be able to cross the others. Also, the cascade thing has not been tested yet and the level is lowered in front to show flow in diagram.

[pedzola]

Maybe I'm a little slow, but how exactly is this different from using an external cannister filter with intake at one end and spraybar at the other?

Of course, this pump is more powerful, but is that basically it?

The only other difference I guess is that you could decorate the tank to make this look like a waterfall? You could get one of those foam pangea backgrounds or maybe make something yourself to make it look really nice... have plants on top of that rear level and stuff....

But that sounds like it would be really hard to pull off and make it look right.

Let me know if theres anything else that I'm missing! This definitely looks interesting, but looks more like a waste of tank space than an effective way to get water flow from one end to the other.

[Vancmann]

No, you are not slow and good questions, I want to make sure that I don't miss anything with the development of my project. Now, I am sure that if you had enough or a really big canister filter, you can do so with a narrow long tank. Mostly it is the amount of water being pumped and the volume of the tank compared to it. I will do the best I can to explain the concept.
Right now with my other 120 Gallon tank, the water goes into the external filter from one end of the tank and comes back into the tank on the other end. That wet/dry filter setup also has a big pump but after all the hoses and elbows, the flow is greately reduced coming back into the tank. Also, the water exiting the filter back into the tank is also slowed downed by the relatively large tank water volume and relatively stagnant water in the 120G tank.
Two key points, I think, is the ratio of the amount of water being pumped compared to the volume of water it is being pumped into and the shape of the tank. Think of a fire hose spraying water into a long pond or lake and expecting water to flow. There will be turbulence where the hose is spraying but even if there was a hole on the other end, it would not flow uniformly, there would just be an intake in one end and an exit on the other. Now use the same hose in one end of a long canal/drain that is not as big as the lake with an exit on the other end. It would be easier to get the water to flow giving it momentum since it is narrower and has closer volume of water compared to the flow of the hose.
I have made the rear part purpousely narrow and smaller so that it will have less water to move. The flow in the rear is really cool but the flow in the front is not as fast as the rear because of its much larger volume. Both flow the same amount of water but the rear is about 1/4 the size of the front so it recycles 4 times every time the front cycles once so it has to move much faster to keep up. Theoretically 4X. To take this further, the 1" hole that water exits the pump flows also the same amount flowing through the tank and I am sure you know how fast it flows there.
Second, the linear length which is about 10 feet is what I wanted to get a longer length tank so that the water can build up momentum and also, give the fish more distance to swim. Hopefully, these fish remember to swim up a small raise in water level against a strong current. The drawing is not drawn to scale so there are lots of room for swimming in the rear. The filters occupies about 15% of the rear. The air empty space above I wanted that for plants so it is not all that wasted
This is all in my head and I can visualise it but it may or may not work as I want it. When I have it finalized and if it works I will vdo tape it

[Vancmann]

Hey pedzola, do you or anyone else know if that spray foam works for aquatic life purpouses? Does it leach? You had mentioned foam pangea.

[Mark in Vancouver]

It's still an interesting experiment - and we like interesting experiments on LOL! I wonder if Martin's rivertank manifold design might not be revealed as a thing of beauty in its simplicity. It creates the unidirectional flow, which can be quite strong if you get into the larger powerheads and wider bore pvc, and you don't lose any tank space, either above the surface or at the rear of the tank.

But I don't mean to discourage you - I'm keen to see the thing in operation. I love weird aquarium innovations. Remember the fish bridge?

[qumqats]

O) wouldn't work for me because all of my tanks are viewable front and back.
O) use two smaller pumps rather than one single pump. redundancy/no single point of failure.
That way you don't lose an entire tank of fish when a single pump fails while you're gone on vacation for a week.
O) how big of a tank are you planning on? The deeper front to back the better.
O) intriguing / ingenious idea! keep up the good work.

[Vancmann]

All the filters are removable cartridges. They could slide out and be open all the way in the back. The setup is flexible so you can add an external canister to do the filter and it also will work as an auxilary for more flow from one side to the next.

[Vancmann]

Here are some photos of the flow, shown with the water level lower than obtimal. I will have to add bubbles so that you can guage the water movement. I can add more pumps to increase the height/flow of the fall. An auxilary pump also works as the systems backup incase one pump fails The center is now reinforced and can handle the pressure. "Fingers crossed".

[Martin Thoene]

Interesting idea.

I understand your point about size of tank vs pump flow, etc.

Your 950 gph sounds a lot, but it's a 120 gallon tank. It will turn over approximately 7.9 times per hour. This is excellent for filtration purposes, provides a one-way current, but won't be up in the performance spectrum needed by Hillstream Loaches, although Botia would probably be happy with it.

I use two Aquaclear 802s on a 65 gallon tank. They're each 440 gph at no head, so 880 gph turns the tank over more than 13 times per hour.

To just exceed that you need two of your 950 gph pumps.

The hardware starts to get expensive as you increase tank size in order to maintain turnover. That's why I have a new concept in my head which I hinted at a few months ago. I do want to pursue the idea, but it will have to wait till next year sometime. It is totally unconventional technology in an aquarium environment, but I believe it will move insane amounts of water.

Martin.

[Mark in Vancouver]

Oh, Martin... That's a tease! I want to know what you're thinking.