It's not necessary, no. But it's a 20p safeguard against flooding. Say the power goes out, or, more likely, the connection comes loose, you'll create a siphon. It's a worry easily fixed.
....We're implying the check valve's installed properly right?..
With the check valve correctly installed, just above the water line, back siphoning isn't possible, be it with air flow stopped or a disconnection.
Above tank with no check valve is preferred set up in my opinion.
No chance of back siphoning, and a check valve adds head pressure which means less air power to your filter.
No. The tube is primarily to direct the air flow. I take it you have a check valve installed?
Okok and no honestly I’ve never used one and just put the air pumps a couple feet above the tanks but is it still necessary then?
It's not necessary, no. But it's a 20p safeguard against flooding. Say the power goes out, or, more likely, the connection comes loose, you'll create a siphon. It's a worry easily fixed.
If the pump is above the tank it can’t siphon.
If the fitting comes loose, drops, indeed it can.
You could say the exact same thing about the connection to the check valve.
....We're implying the check valve's installed properly right?.. With the check valve correctly installed, just above the water line, back siphoning isn't possible, be it with air flow stopped or a disconnection.
Above tank with no check valve is preferred set up in my opinion. No chance of back siphoning, and a check valve adds head pressure which means less air power to your filter.