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Koralia 8

Posted: Tue Feb 02, 2010 7:13 pm
by Curtis
Do you think two koralia 8's would be too much current for a 265 gallon 7 foot tank?


Posted: Fri Feb 05, 2010 6:36 pm
by chefkeith
one of them is 3250 GPH. That's a ton of force from one output. I'd be afraid it would hurt the loaches if they got too close.

Posted: Sat Feb 06, 2010 8:37 am
by Keith Wolcott
In my 9 foot 300 gallon tank I have 4 Tunze pumps that each move 3500 GPH and it is not that strong of a current. Even when I put two of these pumps in a 75 gallon tank it was really quite a strong current, but the loaches seemed to really like it. Thus I think that it is nearly impossible to get too much current for loaches in an aquarium. In an aquarium we cannot approach currents that occur in their natural habitat. For example, I have heard that some rivers move at 1 meter per second. In my large tank, to move the water in a horizontal circular pattern at that average speed, pumps would have to move 220,000 GPH. 63 pumps moving 3500 GPH would be needed to do this, so we do not even remotely approach that speed of current. The current right in front of the pumps is faster than the average, but my loaches and my SAEs can swim right up to them and pick food off of the grating.

Posted: Sat Feb 06, 2010 2:59 pm
by chefkeith
Thanks for correcting me. I had no idea that the pumps that size would be so gentle.

Posted: Sun Feb 07, 2010 3:22 pm
by JonasBygdemo
Also the flow rating of the pumps will probably be a bit lower than the number on the box.

Posted: Thu Feb 11, 2010 4:41 am
by Vancmann
Keith Wolcott wrote: Thus I think that it is nearly impossible to get too much current for loaches in an aquarium. In an aquarium we cannot approach currents that occur in their natural habitat. .
Keith, I believe this but I took it upon myself to create an environment where my loach has more current than they can handle. I did it using my "turbo tunnel" As of now only the two largest can last a couple minutes in the tube before they get pushed out and out of breath for a few minutes. Some areas in the tube they get twisted around but they are always up for the challenge. My new little clowns get super excited but never enter alone. They only buzz around the exit of the tube with the two largest that can do it as if nudging them for a ride or something.

It is a 4"tube x5 ft long with a high pressure 1000gph plus a 300ghh pump. The pumps are placed at the input of the 4" tube to create momentum and vortex thus pulling more water than the pump actually pumps through the tube. I will have to figure how to upload some videos to show you.

Posted: Thu Feb 11, 2010 6:08 am
by Keith Wolcott
Vance- Yes, concentrating the flow in a small area and not letting it spread out as you have, certainly does give you a strong flow. A calculation shows that if you have 1300 gph moving through a 4 inch diameter tube, the water is moving at a rate of 6.638 inches per second through the tube. That's not as fast as I thought it would be.

Posted: Thu Feb 11, 2010 2:50 pm
by Vancmann
Keith like you said but the reason I made the tunnel was due to the fact that it is near impossible to feasably create mother nature's environment in a fish tank. I tried the river tank but like we have concluded, it takes lots to move all that water to anything close to what the loaches can handle.

Now that I have a somewhat challenging flow for my clown loaches, I can observe a behavior that I once talked about when I made the comment you are now saying about creating large flows in a tank. One of my theories, I think that one of the reasons that loaches "dance" or stick to each other when they swim about erratically is an instinct to keep the group together in the event of a monsoon flood. Being of a pecking order and that they know each other, it would not make sense for clans to break up and re form everytime.
Anyways, I will explain my turbo tube in the following post.

Posted: Thu Feb 11, 2010 2:52 pm
by Vancmann
Keith Wolcott wrote:Vance- Yes, concentrating the flow in a small area and not letting it spread out as you have, certainly does give you a strong flow. A calculation shows that if you have 1300 gph moving through a 4 inch diameter tube, the water is moving at a rate of 6.638 inches per second through the tube. That's not as fast as I thought it would be.
Actually I wouldn't apply it linearly, it is way more complicated and I may need your help to figure it out. The concept includes fluid dynamics. Will explain. I have the idea but got to work on the calculations. Also, I have measured the flowrate of the bubbles (just eye-ball because it is hard to pick out specific bubbles) and came up with about 2-3 feet per second. Will have to use a piece of blue sponge to get a more accurate flow velocity.

Keep in mind, the output from the pump's 3/4" tube does not have a sealed connection with the 4" tube. If it did it would be easy to figure out and as the diameter of the tube increased the water flow would decrease proportionately if the volume of water remained constant, which would be the case on a sealed connection. Example: If 1000gph will flow (X) MPS through a 1" tube then that same 1000gph will flow X/2 MPS(half the speed) through a tube twice as big and so on..

Proof, here is where my concept differs: For simplicity, we will ignore resistance and use the one 1000gph pump for now. It is a high pressure mag pump and not the koralia units. My system is not sealed at the intersection which allows the output flowrate from the pump's 3/4 tube to maintain velocity, atleast for a small distance. Newtons first, law of inertia. Now here we have a 4" tube with a jet stream flow right at its mouth. I figured the get stream would eventually slow down the further it gets from its source due to the resistance of the "still" water it must push through. But, at the mouth of the 4" tube, the 12.1fps or 3.7 MPS jet stream causes a high vacuum because the water around the getstream wants to flow at the jetstream's rate for the following reasons:

1. To enter a lower pressure area that the get stream made and in the 4" tube

2. The properties of water surface tension ie the water around(low energy) the jetstream wants to flow with the jetstream(high energy).

About #1, I have tested the presence of the low pressure (vacuum) with an aristone that was held one inch (1") away from the mouth of the tube. The bubbles were sucked horizontal into the tube. Anything further and the bubbles went up. Also, I have seen unsuspecting fish get sucked in at the mouth of the 4" tube.
About #2, too much physics to go into regarding surface tension of liquids.

We can assume the flowrate of water at the 4" tube's mouth as approx or slightly less that the jetstrem's 12.1FPS and gets slower radially towards the inner wall of the 4" tube. BTW, the pump's output hose sits at a slight angle(for tornado effect) and protrudes about 3/4 inches into the 4" tube. I can conclude that a 4" tube with ~12.1 fps rate will flow more than volume than the pumps output in this case. In an ideal world ignoring resistance and with magnetic surface tension, it would be a theoretically very high flow of 28300 gph(in the tube off course) based on my calculations but we both know that this is not possible here on earth with this setup.
For now since I don't have any idea how to calculate the effects of surface tension, fluid dynamics and the resistance, I will have to literally measure how long it will take an object to move from one point to the other and figure the gph from there.

Definitions: Jet stream=the jet of water that shoots out of the pump's 3/4" ID hose, Feet per second(fps), Meters per sec(mps)
Calculations: A 1'x3/4" hose will have to cycle 43,668 times ({volume of water flow/volume of hose converted to gallons}) per hour at a 1000GPH flow rate or 12.1 times per second. In other words 12.1 feet per second since the length of the hose is 1 foot. This is the flow of the jetstream out of the pump.
Calculations based on one pump.

Posted: Fri Feb 12, 2010 5:32 pm
by Keith Wolcott
I think that you are correct Vance, that you will have to put a sponge or some object in the current and measure the speed. I will be very curious to hear the results.

Posted: Sun Feb 14, 2010 6:22 pm
by Vancmann
Keith, Sorry i took so long but I just did some testing. The plants are totally in the way for me to do adjustments if any at all. The problem with the flow is it spirals and more so at the beginning. I did that purpousefully because the clowns would use the current + their torpedo shape+ the inner walls of the tube to easily move up in the tube. Their bodies converted the flow force against them to what ever direction they wanted. Sometimes they can just sit there in front of the pump. But with the spiral flow, they have much more of a challenge.

Results: The tube is 5 feet long and I got 3 results. Timed distance is from beginning to end (5') and were 2.73 sec, 2.31 sec and 2.94 sec.

Details: After releasing the objects, it would just spiral around and move randomly in the first 1/3 section of the tube and also sometimes get hung up temporarily. After it passes half way it just shoots out. It goes through the second half much faster than the first half. The time is therefore and average time for the whole 5'.

I will have to chop some of my "trees" down and do some re adjustment to the spiral flow because I think it is too turbulent for them.

I did another test and possible the coolest ever: Nothing drives my clown loach more than food. Today I hung a piece of their fav lobster tail in the tube and got the alpha fem to get a good bite from it. then I turned on the pump. She hung in there for about 20 seconds sometimes doing a couple spins till she could get a grip on the flopping piece of lobster. Then she would bite a chunk off and let go and glide backwards with the current till she is out of the tube to catch her breath. She actually did it a few times taking 2-3 minute breaks with the pump on. It was cool to see her hesitate for a minute then strggle and swim up the to get another bite.

I have not video taped this yet because my plants makes the tank dark and the glass reflects too much light for the camera to focus in the tank.

Posted: Mon Feb 15, 2010 4:39 am
by Keith Wolcott
That is an impressive rate of flow!

Posted: Mon Feb 15, 2010 12:02 pm
by Vancmann
Retrack the flow back to the koralia 8
I think that the koralia 8's have great flow volume but nowhere close to the power or force to be too harsh for clown loaches, even if it circulated 10,000gph. They are designed to push massive amounts of water but are not designed for or capable of head pressure or strong force. The 18 watt motor of the koralia 8 would not be able to handle much head pressure/strong force. I think koralia are great for reef aquariums where large volume water movement is needed to prevent dead spots yet not disrupt the sand and delicate life too much.

In contrast, my Mag uses a 95 watt motor and while not geared to to move more than 950 GPH, it has the force to move gravel all the way to the other side of a 6 foot tank (without the turbo tube) or create quite a high water sprout. For that reason, I have to make sure it is well secured well in the tank so that it does not break loose and empty my tank.

My point: GPH and flow speed/force are completely different and to simulate a river, the loaches natural environment, the speed is the more relevant of the two. Koralias built for GPH (volume) and power or sump pumps are built for pushing, force, flow speed ect

I have not looked into the koralia 8's much, I just know its concept and specs. I could be wrong about it.

Good experience with Koralia

Posted: Mon Feb 15, 2010 12:52 pm
by bigpow
I also have nothing but good experience with Koralia.
I've 2 K4 in my 125G and 3 K4 in a 240G.

I really like how Koralia wave is gentle and wide, compared to more traditional water pump / powerhead. I was thinking of setting up my 240G using PVC and powerheads, but after my experience with my other tank running Koralia - I changed the plan completely to just running Koralia.
It's a lot simpler and generates a lot more current. It's also more energy efficient and quiet - much appreciated.

Posted: Mon Feb 15, 2010 3:09 pm
I have a tank of 630 liters and use one Koralia mangum No 8.
For me, it's perfect.
My loaches love.