affect on protein skimmer

[rick s]

Hello Randy,

I recently discovered that my phosphates were at 1.0 in my 90 gallon reef tank, light load. That explains my "no growth" syndrome.

I read many/all of your phosphate articles and started using Rowaphos in a fluidized bed filter. I am going slow. I add 2 Tbsp of Rowaphos every 4 days. It has been 2 weeks since I started lowering them and my phosphates are down to 0.25.

As soon as I started using the Rowaphos my skimmer (Turbofloater 1000) stopped producing skimate, at all. The skimmer is working as normal, ie. normal air bubbles, normal flow. The bubbles crest in the same place, they just do not "walk" up the cone of the collection cup.

My hoses are getting coated with brown algae (?) and I haven't had any skimate in 2 weeks.

I understand that changing the water's chemistry temporarily affects skimming. My question is: Do I continue my every 4 day addition of Rowaphos until I reach zero phosphates, and not worry about the skimate? Or, do I need to stop adding for awhile and let the skimmer stabilze for a period of time?

Thanks,
Rick

[Randy Holmes-Farley]

There are two possible reasons that I can think of. One is that the iron oxide binds organics to its surface. This will decrease skimming output for a time.

Second is that some small iron particulates may be released, become coated with organics, and get into the skimmer, helping to pop the bubbles. Is the water at all brownish/reddish from the Rowaphos? Did you rinse it first?

I'm running a bit of Rowaphos right now, and my skimmer seems normal. I did rinse mine first, and my system is fairly large for the amount of Rowaphos that I'm using.

[rick s]

No. My water is very clear.

I rinse it each time I add more by collecting and discarding the first 2 gallons out of the fluidized bed filter. That first gallon is very colored. The second is quite clear. Then, I put the output hose back in my sump and run it as normal.

Should I continue my course of action or stop adding Rowaphos for awhile and let the skimmer stabilize? Which is worse: Phosphates at 0.25 or zero skimming for 2-3 weeks?

Thanks again,

[rick s]

In case it matters: When I feed I turn off my main pump for 30-45 minutes so all the food stays in the tank until it's eaten. All the rest of my pumps in the sump continue to run, including the Rowaphos filter. So it's recycling the same water for that duration.

Is that a factor somehow?

[Randy Holmes-Farley]

I'd keep on using everything as is unless and until you detect some sort of problem. :)

[rick s]

Will do. Thanks Randy.

[Randy Holmes-Farley]

You're welcome.

Good luck! :)