White stuff - what is it
 

White stuff - what is it?
I regularly turn off the return pump for feeding etc and when I turn it back on again I get lots of white bits shooting into the tank. It appears to be a build up of something in the return pipe. Can anyone shed some light on what it might be and how i can get rid it?

Thanks

most likely it's biofilm - i.e., it's thick coatings of bacteria. Generally speaking they're harmless and also unavoidable unless you take steps to eliminate bacteria from your system (which would also destroy your tank).

Do you dose any sort of liquid carbon source? i.e., the prodibio system, zeofood, vodka, sugar, vinegar, etc.? An relative increase in system wide biofilms in places like piping is a direct result of dosing liquid carbon, but they will happen no matter what you do. If the system is old enough for the biofilms to have reached critical mass they are very likely just getting dislodged by the pump turning bcd on.

Sugar and vinegar.

Yup, definitely biofilm then. That white stuff is the heterotrophic bacteria that's keeping your nutrient levels low by sucking up nitrate and a small amount of phosphate as it eats the organic carbon. You don't notice it as much with a BP reactor because the bacterial colonies form in the reactor and are continually sloughed off and skimmed out, but with system wide dosing they grow on every available surface.

I've seen people post on RC about needing to clean out their pipes every so often when they liquid carbon dose because the bacteria can get thick enough to reduce flow rates. The fact that your excess keeps getting dislodged is actually probably a good thing.

Thank you. I better switch to something else.

Will dose zeobak, zeofood, and zeostart.

You may want to use a reactor and the rock to give the bacteria something else to grow on

+2 - the film in your pipes can be cleaned. I think 2 Little Fishes makes a pipe cleaning magnet if you are concerned. I personally wouldn't worry.

If your spending the money for those 3 Zeo products you might as run the zeo rocks in a zeolite reactor to get the full affect of the zeo nutient reduction system.

2 months down the road it would be interesting to know if the the expensive zeo system is "better" than the sugar/vinegar/vodka you were doing.

I don't know if I have room for reactor.

I would try eliminating the sugar and do straight vinegar or vodka and vinegar.
I think you need to wean your tank off the carbon if you switch.