I believe my AFS is working because with the feeding rate I’m giving, it would not be possible to have parameters mentioned above.

PART ONE: QUESTION

Hi it’s me again. As you know lately I’ve been giving my koi heavy feeding again high protein koi food, the only constraint usually would be floating feces indicating the koi have been overfed, thus I would fast them for a day and then afterwards I would continue for a week with staple koi food. Lately I’ve noticed some foam starting to show up near the waterfall. I know this must be a sign of DOC build up, but what confuses me is that all my parameters are in check. Even last night I checked my parameters Ammonia 0, Nitrite 0, Nitrate 10 mg/l, pH 7.5, TDS 58, ORP 470, but there was still some foam showing even just a little bit.

My question is, how does this DOC accumulate in my pond even though I clean my sand filter everyday including 3 more backwashes and a daily dose of clay to coagulate fine debris in order to enable the filters to filter them out faster? I believe my AFS is working because with the feeding rate I’m giving, it would not be possible to have parameters mentioned above.

Due to this problem, again I surfed the web to further learn about DOC’s and from a reef aquarium site it was mentioned that there are no bacteria that we can cultivate to take care of DOC’s, that is why the author advises activated carbon. Here is the link and the excerpt:

http://joejaworski.wordpress.com/2008/05/09/does-a-reef-tank-need-carbon/

QUOTE:

"Don’t confuse organics with ammonia, nitrites, or nitrates. The bacteria responsible for breaking down these nutrients naturally thrive in all aquariums. Most tanks are nutrient rich and provide lots of food for these bacteria to thrive. Organics on the other hand, consists of complex metabolic compounds including phenols, organic acids, proteins, fats, carbohydrates, and hormones. To break these down, we don’t (and can’t) grow the right bacteria in our aquariums. In fact, detritus on the gravel surface and in the bottom of the sump are organic compounds that have reached such high concentrations that they fall out of solution. These particles remain inert as long as pH, oxygen, and ORP levels stay constant. Any wild swings or disruptions will trigger detritus particles to release these pollutants back into solution, causing an avalanche effect that will fuel a tank crash like there’s no tomorrow."

From here I dug deeper into how activated carbon works in solving the DOC problem, and it turns out there are several alternatives which among them were montmorillonite clay Zeolite, both of which I add daily and I use in my BCB’s as a substitute for cat litter. If so then why is this DOC still persistent in my pond. Not wanting to take any chances yesterday I added 3 bags (@1kg) of activated carbon to my pond and I suppose it’s helping because the ORP increased from average of 230-250 to 270 as last measured last night.

I’m not sure if I understood it correctly but activated carbons works similarly to a part of the BCB’s in which it has absorption and adsorption properties. In other words my BCB’s should be doing this. If not so, is there something about activated carbons that cannot be replicated by BCB’s? Is adding some activated carbon of any use in taking out DOC’s in my pond? Or is the problem just I, pushing my pond too far? Hope to receive another enlightenment from you.

Some links to Activated Carbon and Protein Bubbles.

http://anoxicfiltrationsystem.blogspot.com/2014/05/about-sand-filters-state-of-art-in-pond.html

http://anoxicfiltrationsystem.blogspot.com/2014/02/this-article-is-about-association-of.html

http://anoxicfiltrationsystem.blogspot.com/2014/02/part-2-thermodynamics-substances-bead.html

http://anoxicfiltrationsystem.blogspot.com/2013/08/we-had-seen-ponds-that-had-whitish-foam.html

After reading the link given, I regret to say I am still lost. Right now, based on measured parameters, everything is in check. ORP in fact continues to increase after inserting the activated carbon and the foam is slowly decreasing.

What puzzles me is that even though at present the ORP is getting better, the previous ORP was also in satisfactory levels (430), and never have I in the past had foam when the ORP was above 400. All other parameters were also fine. But despite all these parameters being satisfactory I was still having foam. My AFS was still relatively clean from sedimentation/solid waste.

One thing I've noticed is that this foam occurs when my sand filter is operating well, but whenever it is clogged and need backwashing the foam would be significantly less or none at all. I'm now wondering, despite my cleaning out the sand daily, is it possible for the sand in sand filters to accumulate doc's within their pores (if they have any, I have no idea)? I am overdue of changing the sand according to factory recommendation, but because I clean it everyday I figured my sand doesn't need replacing, in fact I believe the sand in the filter is cleaner than new sand which still needs rinsing of debris, but now I'm having my doubts.

Another "suspect" I have are the mats in my Bakki showers, they tend to accumulate mulm under them and also like you said they are covered in cyanobacteria. 

So here I am still lost, but the activated carbon still seem to be helping. I've browsed around comparing Zeolite vs. activated carbon for purposes of taking out doc's, it seems so far Zeolite is for taking out ammonia while activated carbons are for taking out doc's. Is this correct? Comparing activated carbon with foam fractionator, which would you advise? Again I hope this email doesn't catch you at a bad time. Hope to hearing from you soon.