I have a question.

So we have an undergravel filter with the tubes that bubble. Well they both have a buildup in them.

We were told that is normal and its good bacteria. Is that true?

When we move we are going to take almost all of the water out of the tank with us that way we dont shock them to death with new water.

Anyways should we leave the tubes "dirty" like that or clean them?

I always keep my tubes clean. I've never used an undergravel filter.

Keep the filter and tubes untouched (Tony and I used to have a huge tank). If you clean out that good bacteria you're tank will be less stable.

Keep the filter and tubes untouched (Tony and I used to have a huge tank). If you clean out that good bacteria you're tank will be less stable.

Yea we always keep our filter untouched with the exception of the biomedia when it needs to be cleaned. I'm thinking more along the lines of my turt tank. Since the water has to be kept so warm the tubes that are in the tank have to have the outsides scrubbed b/c of the algae. But the inside we never touch. Come to think of it tho on both the other fishtanks we've never had a buildup of anything on them. Inside or out.
Again tho your right Sarah b/c I'm thinking more along the lines of a high heated tank not a normal fishtank.