Airline Slip Out Options

[jhansolo]

Dear Bros,

I have experienced many times the air line slip off from my rena 200 air pump. Anyone experience this? I'm using the ones that Darwin sell blue color soft airline, should I change them?

[jhansolo]

Thanks for all the replies ...

If I guess correctly, the "blue soft" airline tubing you are using is the newer type made of silicon.  Those typical clear harder ones are made of plastic (of some sort.)

The silicon type, I find better in staying connected.  They were made specifically to stay soft (and hence huggy) instead of harden up over-time and lose the grib.

So I'm guessing (again!?) that the fault may lies in your Rena's air-outlet tip.  Is the tip oily and so slippery?  Use some thinner to carefully remove the oil if you can. 

Yes the air line or tubing is the newer type made of silicon. It is wonderful and I really don't notice any smell.

As for the outlet tip, during my last water change ... no there is no oil or whatever, but cleaned it anyway.

Does the air pumping out from the Rena flow freely?  It could be your airstone is clogged and the back-pressure created is so great the connection slips.

Well the stone can't be clog as they are new.

After cleaning,before slipping on the air tube simply snip off the part that was previously attached to the inlet as that portion is likely to have lost its elasticity (hardened) due to the heat emitted from the air pump.

Done that as well ...

I also wrote to Rena and got a reply to add a elastic band, well I figure the main reason for the back pressure is because I place the pump below the water line. Let me do what they recommanded first and see how it goes.

[HappyBuddha]

I also wrote to Rena and got a reply to add a elastic band, well I figure the main reason for the back pressure is because I place the pump below the water line.  Let me do what they recommanded first and see how it goes.

Elastic band? A cool looking high-end airpump now looks like it belongs to a nerd.

About placing below water line. That's a big no-no, you know? When the pump is turned off, effectively the airline tubing becomes a siphoning tube and will draw water into the pump, short-circuiting it. It's a fire hazard! If you don't have a choice but to place it below water line, get a one-way check valve for airpumps asap. It contains a small trap door that prevents water from flowing back into your air pump when power outages occur. It costs about $2 a piece. Most LFS will have it on sale.

[square_guy]

Elastic band?  A cool looking high-end airpump now looks like it belongs to a nerd. 

About placing below water line.  That's a big no-no, you know?  When the pump is turned off, effectively the airline tubing becomes a siphoning tube and will draw water into the pump, short-circuiting it.  It's a fire hazard!  If you don't have a choice but to place it below water line, get a one-way check valve for airpumps asap.  It contains a small trap door that prevents water from flowing back into your air pump when power outages occur.  It costs about $2 a piece.  Most LFS will have it on sale.

not really. the airline tubing will only becomes a siphon if there is a transient negative pressure (when the pump is switch off) in the tubing that is large enough to suck water above the waterline to the topmost portion of the tubing. i haven't see this happen at all even though my airpump is always below the waterline.

disclaimer: i am not responsible for any fire that results from this

[HappyBuddha]

not really. the airline tubing will only becomes a siphon if there is a transient negative pressure (when the pump is switch off) in the tubing that is large enough to suck water above the waterline to the topmost portion of the tubing. i haven't see this happen at all even though my airpump is always below the waterline.

disclaimer: i am not responsible for any fire that results from this 

It has happened to me (although I caught it soon and no serious damage done.)

But come to think about it, you're right. Not only is a negative pressure (effectly priming the siphoning action) is a pre-requisite, the airpump's assembly must also "leak" and not air-tight. The later can happen when the pump is of low quality or the rubber diaphram worn out over time.

Nevertheless, the one-way check valve is a small investment for a peace of mind.

I often wonder if it reduces the pump's output though....