# help with canister filter for paludarium



## Bokfan1 (Oct 17, 2010)

Im in the process of building a 55gal paludarium but I've come across a problem with the canister filter I'm using. This is the filter im using: CF300 3-Stage Canister Filter - 264 gph
And this is how it is to be set up:




The problem is getting the water to be siphoned down to the canister and then pumped back in. I can hear it running but very little lck getting it to pump water. sometimes i can get it to run for a few seconds and then it stops. Ive made sure all connections are snug and no loops in the tubing (I plan on switching to rigid PVC). The tank is only half filled so that may have something to do with it. ANY help would be VERY appreciated. THis is the first canister filter Ive dealt with. 
Thanks in advance for any help!


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## jpstod (Sep 8, 2005)

way to power full of a pump for approximately 25-30 gallons of water. Your drains simply can not keep up with the out flow.

With that pump you will need a drain system which would displace 4+ gallons a minute.

What size of drain are you using.

I seriously doubt you need a water turnover of 10+ times per four


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## Bokfan1 (Oct 17, 2010)

im using the included tubing i think its 5/8 in.


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## VivariumWorks (Feb 27, 2008)

It could be an issue of the drain not being fast enough to allow the canister to be filled, but I've done <10 gallons with a 300+gph canister before with a 1/2" bulkhead sucessfully. (Not my idea. It was a client's...believe me... I know it's overkill nor ideal. When I turned it on full blast, it shot a 1/2" stream of water clear cross the garage, freaking fire hose style. LOL)

What is happening is likely two things:

1. There is air in your canister and inline tubing. This happens when first stetting up most canisters with a vivarium due to the fact that the water is being pulled up a long ways away from the water depth. A way to jump start this easily is to put a basic submersible pump inside the tank and "prime" the canister filter by forcing water into the filter intake line. This will guarantee most, if not all, of the air will be pushed out of the system. Make sure all connections are fully open and keep the pump attached until water comes out of the "out" line from the canister and into the tank. Make sure the out line is unobstructed.

2. The canister filter is pulling too fast from the tank and a cyclone is being formed and air is getting sucked into the line. The way around this is to increase the depth of the water, OR to put a 90 degree elbow on the intake line so that it is not able to form a cyclone as easily. Perhaps both. It depends on where your intake line/bulkhead is located/water depth. Also try scaling back the pump speed once it gets established and slowly increase the speed. Sometimes there will be a cut-off speed at which the pump/bulkhead diameter/tank depth can handle before requiring adjustment. 

If you don't have an extra pump around, a final trick I've done is to disconnect the out line from the pump. Have a bucket ready. Using the prime button, pump this up and down until water begins to flow into the canister (your canister should already have water in it btw). Then when water moves down the intake line and begins flowing out of the open out line into the bucket, you switch the valve to block all water movement, attach the out line to the canister and let water equalize into that line. Then turn on. Should run with only a little bit of air "grinding". Sometimes the air pressure inside the outline tubing is a bit too strong for the water to push against while trying to move down into the canister filter. By removing this line you reduce the pressure. I have to do this trick everytime with the cheap Cascade 500 canisters I like to use. But the good thing is once it's established, if I do the bulkhead right, I can have <1/2" of water in the tank and a full flowing canister.

Hope this helps. Using an extra pump to jump start the priming is the easiest but be sure that you are not pulling air into the line once you get it started or else it's pointless.


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## Bokfan1 (Oct 17, 2010)

Thanks for all the help! I do have a question though: you referenced a bulkhead several times in your response. I currently am not using one, and I currently am not using one Im using the included pipe that exits out the top of the tank (see video above). Could his be a big part of the problem?
Thanks again for the help.


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## VivariumWorks (Feb 27, 2008)

Yes this is part of the problem. The difference between the water height and the tallest part of the tubing is what you probably having a hard time overcoming. This can be addressed by using the extra primer pump to push water up that height to get it started. Though really if you are going to go with a canister filter you should just go ahead and drill the tank (not the bottom) and use a bulkhead. I don't drill the bottom of tanks and don't recommend it even though many on this site do.

The issue with drilling and bulkheading the bottom versus the back is that you have to have the tank on a stand that can handle the bulkhead on the bottom. On the back you can put the tank on a flat surface anywhere. This is very helpful when building the viv and transporting it. Broke a tank in transport when it slipped off it's supports and the bulkhead got the full force of the tank's weight and shattered the bottom, so now I only do the back.


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## Bokfan1 (Oct 17, 2010)

Ok great! i was already planning to install a bulkhead for an overflow. where should I drill the hole in reference to the water level (above, below etc.)? Also I got the tank off craigs list and am no longer in contact with the seller. Is there a way to tell if the glass is tempered or not? Since I dont know who made the tank..


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