Any Idea What This Is?

[Jeff]

Just a quick question, now that I'm really inspecting my two year old system more closely. Since my mass fish die off recently, I am overly paranoid and trying to rule out things as the culprit.

I've noticed that on my return PVC pipes (feeding water back into my tank), there is a crusty substance all over it:

[attachment=0:11a2tcg9]WeirdStuff.JPG[/attachment:11a2tcg9]

Any idea what that could be? It's that off-white color and you can see it on the 90 degree elbow. You can really see it around the bar code in the picture above. Is it just gunk? Is it water deposits from hard water? Is it some kind of calcification? More importantly, do you think it could poison the fish?

It seems to chip off easily if I run my fingernail over it.

I have never cleaned these return pipes (ever), so what you're seeing is just from two years of running the system. The water coming from these valves is what's being returned to the tank from the hydroton grow beds above.

Looking forward to your thoughts!

[Oliver]

We have the same thing here. It is all of the above and I do not believe it is harmful to the fish.

Oliver

[Jeff]

Oliver, that's good to know! Thanks for the response!

[JCO]

I have the same thing...it's probably from nutrient rich water splashing up on the pipe and over a period of time, the bacteria in the water die and layer after layer turns it a dark color. Doesn't bother my fish, infact I usually just rub it off with my hand and put it back in the water it came from :mrgreen:

[Jeff]

I usually just rub it off with my hand and put it back in the water it came from :mrgreen:

Interesting! I admit that I'm a little scared to do that since it looks so nasty.......but perhaps you're onto something there. I wonder if it's like a little fish snack? :lol: Or possibly it will break down and help feed/benefit the bacteria colony in the system.

[Aloha Don]

Thanks for this thread..
I have the same on my piping....I just assumed it was normal because the water is not exactly clear either. I was thinking it is just the efficient water from the FT collecting on its surroundings.

[JCO]

Most likely of suspects is a calcium deposit with particulates and bacteria mixed in, that's why it flakes when touched.

Most water contains calcium whice is leached out of sandstone in the earth as the water passes through it.

It is basically everywhere and that's what it does over time when the water laden with it is exposed to air, as in spray or splashing, where it can dry and build up. :mrgreen:

[multifasited]

I reminds me of the discussion of the worms adding waste to a grow bed {Dirt} they can only eat what's is there in a different form ,same with water unless something is added ,It is just another form of what is already there ,solidifying for one of several possibilities .A de-ionizer is used to keep minerals from separating and collection on surfaces ,nothing to worry about ,just part of the process, if it were going to harm your fish ,It would have before you saw it .IMHO.

[topz]

I have the same scales here on my fittings. I would look for new changes to the system if your fish died off suddenly. Maybe even a new ingredient in chelated iron supplements?