What is this slime ?

What actually is this slime that has built up on the pump tube. It only builds up on the tube and no where else really.

One of the problems with having seen a lot of things is that you get older, and your eyes just don't do it for pictures like that. Usually, I get a brownish biofilm in intake pipes - it seems to like the moving water. Occasionally, I get a dark green, strong smelling slime that is Cyanobacter (it can also be a dark rust colour).

yeah i would say this slime is sort of a green/brown colour and it did have a strong smell when i wiped some off with my finger. This is on the outside of the hose, so there isn’t really any water agitation around the hose.

I suspect it is harmless, i’m just curious to know what it actually is

If it is Cyano, it is an unsightly pain in the $$$ that spreads in unbalanced tanks. There are more threads on fighting it here than you probably can imagine.

When you say unbalanced tanks, what do you mean by this

In a tank where the nutrients in the water are out of whack, a bacteria like Cyano can thrive. The most successful ways of dealing with it I've seen have involved plants and ferts, the problem being that most of us don't know what minerals we have in our water. I used very small doses of Potassium Nitrate to control it at my old house, til I couldn't get the stuff because it is used in explosive making by the US militia terrorist groups. That was a suggestion from a very old fishkeeper, and it impressed me. After the supply issues kicked in, i use a 3 to 5 day total blackout, towel over the tank to derail it now. In my new house, it doesn't expand quickly, and just kind of sits there in one or two spots. I hope that's what you'll see.
I found it went crazy in tanks with water wisteria plants - they must have consumed minerals that suppressed it, because invariably, if they went in they were Cyano coated within days. But in my new environment, post move, I could probably grow them with no problem. It's an organism, possibly the original one, and it's tough. What works for me may not work for you.
I didn't take those chemistry courses I should have.

ah right, that makes sense. Suppose i’ll just have to monitor it and make sure it doesn’t start to spread. Hopefully it will just stay on the pump hose, where it can’t be seen. I’ll definitely avoid adding any water wisteria in my tank.

Thanks Gary!