Fluval 403 filter hose issues

[wilson3821]

I purchased about two months ago a used 75 gallon aquarium with a Fluval 403 canaister filter system. Upon setting it up I install a undergravel filter and replace the two hoses coming out of the back of the Fluval. The used ones were black and nasty on the inside... Today I notice that the clear hoses I put on are starting to form what appears to be algea on the inside of them... The tank is clean and still test correctly. My question is... is this normal or do I need to run some algea treatment through the system. If I do treat the system how does this effect my algea eating fish...

Thanks!

 

[Great Lakes]

This is a normal occurance. They make a brush on a long piece of wire you can pull through the hoses periodically.

 

[macpegg]

Great lakes is correct as i`ve got a fluval 403 thats what i had to do

 

[wilson3821]

Thanks for the information....