Python - not working correctly

[jarrodaden]

My python works really well for the first couple of gallons and then the flow drops to little or nothing.

Lately, once I have a siphon started I just disconnect the "tee" and let it gravity drain.

Any ideas what is wrong here?

[Mzungu]

Are you talking about when you're draining the tank?

I'm new to pythons, so my advice is definitely limited, but have you checked where the hose connects to the python's tube (gravel vac) and to the "T?" Sometimes debris/snails/etc. can get caught and slow the flow.

Also, just making sure, but when you're draining, you have the faucet on, correct? And the "T" is turned so water is coming out from the bottom?

I know those may seem like silly questions, but you never know.

[jarrodaden]

Not silly questions, but I have checked all of the above.

Small snails, etc. might be the cause. I never checked the "tee" after disconnecting it because I had good gravity flow.

[PhishPhreek]

a syphon works because the water level in the "From" container is higher than the water level in the "to" containere and the flow rate will decrease as the water leve drops.

A python works because the flow past the pito tube causes a vacuum. As long at the flow from the faucet remains the same the suction remains the same. If your flow rate frome the tank decreases then something is pluging the passageway.

[rage]

Whether it's a python or siphon, it works because of pressure difference.

I would guess, the flow rate coming out of your faucet is lower than before, hence lower pressure difference or your tank water level is not much higher than the outlet, hence smaller gravity difference.

Another thing, if you have air in the line, it would be hard for the pressure difference to push the water.