# Question about "overdriving" a Fluval 104



## Aaron (Feb 12, 2004)

Here's my dilemma, I have a fluval 104 hooked up to 22.5 gallon tank (12"x12"36") and it is pushing water thru a tetratec UV5 and a 1.5' DIY reactor. As you can imagine, the flow has been greatly reduced. Would I run into a problem if I hooked up an inline water pump to one of the hoses to increase the flow? Would I want to put it before or after the canister? I have a couple of magdrive pumps lying around and it would be nice if I didn't have to spend more money on this tank.


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## titan97 (Feb 14, 2005)

Any pump that requires its own fluid as a lubricant needs to never be restricted at the source. I would try to connect one of the magdrives to the UV sterilizer or the reactor. I wouldn't install a mag drive pump inline with any other pump. Magdrives are notorious for decoupling if driven without the correct amount of fluid passing through them. Since you have 2 magdrives, why not connect each one to either the reactor or the sterilizer?

-Dustin


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## Aaron (Feb 12, 2004)

Forgive my ignorance, but what does "decoupling" mean? What if I put the pump in front of the cannister? Would I just screw up the motor on the fluval with having an excessive amount of water pressure running through it? 

Would a direct drive pump like a Beckett or Iwaki be better?

I really want to keep the least amount equipment out of the tank as possible. Any other suggestions?


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## titan97 (Feb 14, 2005)

Magdrive pumps have a impeller connected to a magnet. All of this is contained within the pumping chamber. On the outside of the pumping chamber is usually another magnet. The seal for the intake and output of the pumping chamber is pretty tight in order to maximize pumping efficiency. Magdrive pumps will decouple (the impeller magnet will come loose) is not run correctly. They require enough fluid flow to cool and lubricate the pump assembly. 

Placing another pump infront of your canister will do nothing but consume electricity. Your canister can only push out so many gpm. Increasing the input pressure MIGHT increase the flow, but not by much, and I wouldn't recommend it. If you are going to use the magdrive, why not connect it directly to the reactor or UV? It will require more tubing, but you will get the best setup. It sounds like you are pretty set on using the magdrive inline with the rest of your setup. You will only cause yourself more problems this way.

-Dustin


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## dennis (Mar 1, 2004)

Could the magdrive be used in a loop to power the UV and Co2 stuff? Would one be able to run the loop from the infeed line of the canister filter if it was a seperate loop,ie, use 2 T connectors in the inline for hte canister?


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## titan97 (Feb 14, 2005)

The magdrive SHOULD be used on its own loop. The problem with making a T on the intake of the canister is now you have 2 pumps drawing from one hose. The suction will increase dramatically, and you might start to starve one of the pumps. Starving pumps is the cause for the majority of pump problems. And T-ing the output line will increase the pressure going back to the tank. While not as bad as the T on the intake side, you might not like the force caused by the large amount of water going through such a small hose. Also, the backpressure created this way COULD cause a loss of pump efficiency as now one pump has to fight the other and vice-versa. 

So, ideally, you should run the magdrive on its own loop with its own intake from your tank and output to your tank.

-Dustin


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## gpodio (Feb 4, 2004)

Besides using a separate loop, you could try to place a mag drive pump after the canister, before the rest of the items and actually remove the impeller from the canister so that only the mag pump is moving water. As mentioned above, there will only be so much water you can push through a certain diameter hose before you start getting into pressure problems, be it too much pressure on the output side which could lead to leaks or too much negative pressure on the intake/canister side leading to eccessive outgassing and constant bubbling and burping as the bubbles pass through the pump.

As for the chances of the mag pump impeller "decoupling" I think it's somewhat rare, there is sufficient space between the impeller and the housing for it to keep turning even when the output is completely blocked. You would have to restrict the rotation enough so that the frequency of the power source causes the impeller to start vibrating back and forth rather than completing a full turn per cycle. I've had clogs and restrictions happen several times and the major risk in my opinion is overheating the coils due to no water movement. As a further step to reduce the possibility of an impeller failure due to resistance in water flow is to use a smaller impeller than the one supplied with the pump. Most Mag pumps can run an impeller from a smaller mag pump, I run a Mag5 impeller in my Mag7 for example.

Good luck with it, I do feel a separate loop would be the ideal solution but it's a small tank and you're probably not looking to have more tubes around it than you need to.

Giancarlo Podio


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