I screwed up again! Canister help.

[anonapersona]

Next time...

When you did the 90% water change, the water level went below the intake of the filter, so all the water drained out of the input tube, but water stayed in the tubing behind the tank. when you refilled the tank, the air in the tank side of the input tube got compressed as water rose in the tubing. Sometimes the canister can handle this, if you let the tank fill to the top before trying to restart, and if the output line is high in the tank so that air can get out of the spray bar. (this happens to my discus tank when I do more than a 50% water change.)

If you restart and the flow seems wrong, first look behind the tank to be sure there is no loop in the line where that slug of air got stuck. You can usually just bend the line to allow that air to flow on through.

If that does not work, you can stop the filter then unhook the tubings. Get a bucket and carefully aim, manually open the lever that locks the valve and shoot some water from the tubing into the bucket. The input line will clear that bubble, the output line may go dry, that won't matter. (not sure if you have separate lines or lines together like the 2026).

You won't need to worry about water in the canister itself, it is OK to keep filled. All you need to do is to clear the air in the imput line. Trying to do that by sucking on the output of the canister if the canister is full of water is a bad idea, but works fine if the canister is empty. Ditto for sucking on the output tubing at the tank level, works fine when the tubing is empty, not a good idea if that tubing is wet.

 

[hurricanejedi]

Ooooh ok! I'm glad I got it to start though. But next time I'll drain the water out of the tubes as that would probably have made my life easier. I was in such an akward position because the tubing goes through a whole in my stand out the back. So I'd have to somehow empty part of teh water otu the tube then empty the rest of the water after I pull the tubing back through the whole.

I think I'm sounding confusing now.

Maybe I'm not completely understanding. How exactly should I shut off my filter next time so this does not happen?

 

[anonapersona]

Ooooh ok! I'm glad I got it to start though. But next time I'll drain the water out of the tubes as that would probably have made my life easier. I was in such an akward position because the tubing goes through a whole in my stand out the back. So I'd have to somehow empty part of teh water otu the tube then empty the rest of the water after I pull the tubing back through the whole.

I think I'm sounding confusing now.

Maybe I'm not completely understanding. How exactly should I shut off my filter next time so this does not happen?

Yes, you are being confusing! First, what filter do you have? Knowing that will help us here.

Second, you always shut off the filter before you change water. In fact, the best idea is to have a power strip with an on/off switch and have heater and filter plugged into it, maybe lights if you can see well enough to clean the tank with tank lights off. Then, when you drain water, before you start, hit the switch to stop the filter and heater (and lights if connected). This will help you to never have a heater running when the water level is too low, the heater will get real hot and when water hits it as tank fills up it will crack, perhaps breaking glass in tank, perhaps electrocuting you and or fish. I like the Fire Shield power strip with built in GFI, approved for aquarium use (most are not) and about $12 from Walmart.

Anyhow, draining the tubing is done from the valve at the canister end of the tubing. You don't want to mess with the hoses behind the tank if you can avoid it. You'd disconnect the hose, like you were going to clean the canister, and just manually open the valve to shoot water out the hose into a nearby bucket. This is a good practice to do during normal cleaning as it will help clean the crud from those tubings (so after you clean the canister and tank there is not a bunch of crud that shoots out the hoses into your clean tank) When you backflush the tubings this way, if the input tube is still in the water, it will flow hard enough to clear any bubble from the line and the output line will only flow until it is above the water level and runs dry.