River tank manifold water flow

[Diana]

I did a little work with my 20 gallon long tank.
This tank is 30" (75cm) long, and 12" x 12" (30 cm x 30 cm)
I have an Eheim Ecco 2234 with the intake at the left lower back corner and outlet at the right upper back corner, aimed slightly toward the front of the tank. It hits the front glass more than halfway toward the left end.
I have an Aquaclear power head also on the right end of the tank, pretty close to the middle of the right end. Intake is at the left end of the tank, just about the middle of that end. It also is aimed slightly toward the front, and hits the front of the tank just about the middle of the glass. The flow from these two sources starts out parallel.
The Hagen site (they make Aquaclear) says 270 gph (But take that with a grain of salt) 145 gph for the Eheim.
With somewhere between 300-400 gph (1200-1600 lph) on a 20 gallon tank there ought to be something like a river going on in there. I have Darters in there, a lot like Schisturas.
Decor is relatively open, rounded rocks on the floor of the tank, a couple of pieces of small driftwood, some plants that stay low.

There is some duckweed at the surface and I can follow that around to figure out what the water is doing at the surface. There are not really any plants in the middle of the tank to watch. There are a few plants at the left (intake) end. When I pull off the sponges the plants try to enter the intakes. Other than that I cannot tell what is going on lower in the water. These plants do not move much. They are sort of stuck at that end, though, they do not grow out into the rest of the tank. Certainly I can stick my hand in and feel the power head, but anything finer than that is probably affected too much by my hand being in the water.
The surface is swirling around, clockwise. This seems to be due to the Ehiem. The outlet is aimed this way, and the movement continues, even when I unplug the power head. There is no vortex, though. Just swirling Duckweed. (It must get dizzy!) There is a small anticlockwise swirl in the front right corner.

Spas and Swim-spas:
My company has installed a few Nespa swim-spas. They are not exactly the same as an Endless Pool, but the idea is the same. Their basic design is a 2-part spa and pool, with a wall in between (the wall is optional, but gives you a spa on one side and a small pool on the other.) If you want the pool section to have a strong flow so you can swim laps (Endless pool style) they will set it up this way. The equipment is similar to a full sized pool, so all the normal inlets and outlets found in a large pool are concentrated in the small swimming section of Nespa's Swim Spa. Pumps up to 3 hp are detailed at the Nespa website, with performance up to 160 gallons per minute (yes, per minute: this is 9600 gph) This swimming section can be made to order, but several of out clients have ordered it roughly twice the size of a normal spa so there is room to swim in it with a good current. Without the current it is not much more room than an oversized spa, and an adult would not likely get more than about 2 strokes before hitting the end.
This is all remote equipment, similar to a swimming pool.

Relating this to an aquarium: You could probably design a similar thing, plumbing and remote equipment, but the inlet and outlet design and layout will be critical to give you a good river flow. There are likely to be counter currents in any set up, though, even if you figured out how to make the entire area of the end be the inlet and outlet.
As noted several posts ago: even a fast moving mountain stream has quiet pockets, and sections where the current is flowing 'backward'.
To give the fish a choice of water movements is very important. As much as they need the high flow, high oxygen set up, they also need quiet places. Many of the Hillstream fish do not spend so much time directly in the maximum flow of the water, but wait in these quiet pockets for an insect to land on the water or swim by, and dart out to get it. Darters, for example do just this. Mine are rarely right in the flow, but are usually just out of it, perched on a rock or the substrate. There are of course a good selection of fish that do stay right in the stream, too.

Another problem with adding more and more pumps: Most of these are water cooled, and the water that cools them is the aquarium water. By the time you get that much water flow in such a small volume of water you will probably be overheating the water, especially in the summer.

[chris1932]

Shutting off my 5/8 hp river tank pump saved me almost 110 bucks a month. It was the closest I had gotten to true directional flow. There are photos of the tank on here somewhere.

[chefkeith]

Electric bill?
Purchasing costs?
Noise?

The method I use is fairly green. I get good flow with not much electrical consumption and noise. For the 1 foot per second water flow around the island, the total wattage is only 96 watts.

I normally only use a 850 gph Koralia 3 pump that uses only 8 watts and 4 canister filters. The two 20 watt Filstar XP2's have a rated flow rate of 300 gph and two 24 watt XP3's have a rated flow rate of 350 gph, but the actual flow rate is probably less than half of that. When I want a little more flow, I'll turn on another powerhead, which is a 20 watt Aquaclear 70 (802) with a Quickfilter that gets 400 gph of flow

Cost- I probably spent around $500 for the filters and powerheads. Monthly electrical cost for the filters is about $5 per month.

Noise- It's fairly quiet. I don't use anything loud to my ears. What I'm more concerned about is not having too much motor noise or vibration inside the tank that might bother the fish. Soon, I will be replacing the Korolia 3 and Aquaclear 70 pumps with two Eheim 2026 canisters that I have in storage. This will eliminate all the vibration and noise in the tank. I won't put any media inside the Eheim canisters because I hate cleaning them. I just want to use them for the additional water flow.

DIY Creativity Skills- I guess this is the biggest challenge for me. Building a nice island has been no easy task. I'm currently in the process of building a new island mainly because the old one is lacking the natural aesthetic qualities that I like.

One drawback to the island method is that the island takes up about half of the tank space. The good thing is that the island is also a large cave for the fish to swim and rest in, so that space is not wasted.

I do have other components to my aquarium system, such as a water bridge, a calm 85 gallon tank that fish can swim to, a paludarium to grow plants, a sump, two air pumps, and few other filters. These other factors or costs aren't included because the river tank can be a stand alone tank if I wanted it to be.

[Martin Thoene]

You know what? One of those receiver hitch boat-propellor plugs might be a relatively cheap and compact unit if it could be adapted to a drive-shaft.



Replies here are all coming up with the problems we've discussed in the past. To get oomph costs money in multiple, or high powered pumps. This creates heat which is an enemy with Hillstreams. It can also create big electrical bills if high consumption equipment is used.

An Endless Pool type of system seems to be the ultimate answer, but in our case we're not looking at a human swimming in the inner box. They're not going to get sucked into the system like a little fish will. Providing adequate, spread out inflow and outflow for the fish whilst preventing them getting into the works is the key. Not necessarily difficult, but you have to consider required maintenance to maintain flow at peak efficiency through whatever permeable end walls you make.

Martin.

[hx]

Hello, good people at Loaches Online. Been watching you for awhile. Nice forum, thank you.

A couple of cents to the topic of good flow with low electricity/heat.
Im running a "mattenfilter" in my 250 gal tank with a Koralia 4 pump. The setup is as follows:

front:


side of the chamber:


Koralias or Tunze stream pumps are very cost-efficient pumps for moving good amounts of water.

I have a stream tank, measuring 240 x 40 x 30 cm or 8' x 1'4'' x 1'. I am using one Tunze 6060 pump to make a current. The current is directed from one end to the other behind a fake rock bakcground.
It is made for hillstreams.
I'll try and take a couple of pics of it and maybe start a thread later.

[Martin Thoene]

Looks very interesting hx. Welcome to LOL, I (and I'm sure others) would like to see more.

Martin.

[chefkeith]

hx- Welcome to the forum. Thanks for the info. What you did with the matten filter and the Koralia pump is a great idea. I had no idea you could rig a Koloria pump like that.

[hx]

Thank you, gentlemen. Martin, thanks also for your effort on distributing knowledge on loaches and their care. Great job.

Yes, Keith, my idea was to give an idea of the possibilities of those stream-type pumps. To my mattenfilter construction the Koralia fits like a glove, since installed the way I did, it doesn't draw all of its flow through the filter, but partly through the part that is left in front of the chamber. There is a certain flow per surface area that mattenfilter works best, and to the size of mine the whole rate of a Koralia 4 would exceed this rate.

Anyhow. Tunze is a bit different, actually a whole lot easier to rig to give the whole efficiency to circulate to the desired direction. I'll try and get a few pics up today to give an idea of what I mean.

[hx]

I'll try and get a few pics up today to give an idea of what I mean.

I truly surprised myself:
http://forums.loaches.com/viewtopic.php?p=152832#152832