Yesterday on the Reef Moonshiner’s support group owner Andre Mueller posted the following information.
DOC Reduction and a specific CAC (Catalytic activated carbon), investigated closer on the Reef Moonshiners Test tanks and trialed numerous times in the Reef Moonshiners community, proven and repeatedly measured the best solution for gentle and simple DOC reduction for most Reef Tanks. A few scavenging media such as Purigen, granular activated carbons and resins and methods have been tested and compared. So far this following method sticks out significantly and seems most useful from all the options out there. The impact on Trace elements is very very little due to the superior catalytic carbon thats used here.
Here is what you do, but stick to the description and guidance:
Do use the excact CAC as I mentioned if you go this CAC route for DOC reduction!
Buy this particular Catalytic activated carbon, nothing else, don’t ask for others, simply use this particular CAC, many others already use that by now. The impact on Trace elements is very very little for the purpose of detoxifying and filtering the DOC and other undesired more complex chemicals out that were introduced to your tank in some way through water, skimmer air, hands, equipment etc. out. Other GAC’s or other ROX or Hobby grade Catalytic carbons tested have either released certain traces or were absorbing excessively other traces. So this brand was performing really well so far.
The clear Disadvantage is, this is a full box of CAC, but no worries, it will be used over long time and has other useful treatment benefits if used occassionally to reduce DOC levels or filter out complex disinfectants or other chemicals that made their way into the Reeftank.
Simply add this low dust carbon into a zipper media bag from Amazon or local stores ( https://a.co/d/elRbx8C ) and rinse under tap water. After that just add the bag with carbon (approx 300ml CAC per about 100gallon) passively somewhere in the sumps last chambers post the section where the skimmer is. See below some more ideas how to apply it.
You can then keep the bag in the sump for a month at least or longer until the DOC is down into the 3 range as per your Reef Moonshiner’s ICP-MS test which represents the DOC value in form of the SAC254 value in the test results.
Then as soon SAC254 of ~3 is reached, remove it or leave it in. It seems it’s very effectively remove DOC for about 3-4 weeks prior useful saturation is reached. HOWEVER it also can bring down DOC levels well below 3, into the below 1 range which is where I have seen that stripping the DOC and other biological needed compounds in the seawater matrix out too much, have taken away some fluorescence and caused fading colors. More work to be done on this, and more experience is needed. But this is a solid start on this subject.
So that means as soon you have reached the lower DOC level, take the CAC off until a newer test show the need to bring it back in the system.
There are many other carbons out there that do not do perform that long or well, and are impacting the trace elements too heavily.
The above carbon is used to make Drinking water in House filtration systems.
It is much finer in granules, and if you apply it into a media reactor, then sandwhich it between 2 layers of Sera Filter fleece ideally. Reactors however make Carbon clog, which causes then often that carbon deteriorates inside the reactor and leeches elements out, or even cause fouling/decomposition compounds and acids to be released into the water.
The passive absorption of this carbon in a mesh bag in the sump was doing in all tests so far an excellent and easy job, it even impressed me a lot to see the numbers by this passive method of absorption with this CAC brand.
Another advantage of bagged media compared to use it in a reactor is that the media in a bag is always in oxygen rich water, and the risk of anerobic zones in the media is not truly zero, but much lower than in a detritus clogged media reactor!
Another idea is, as this is a very fine granulated media, to add a few spoons after soaking and rinsing into the filtersocks routinely and only so much that over time the DOC levels remain somewhat constant. More ideas and applications are coming for sure and will be shared, but I hope this answers the most important questions for now.”
Main image credit = https://www.completehomefiltration.com.au/carbon-filters/
