Starting Carbon Dosing

[thewbell]

I have been reading up on carbon dosing and have found some conflicting information. I transferred to my new tank (kept LR from old tank so no cycle) in early February and am determined to not have an algae issue. I have been testing nitrate and phosphate and they are both 0 while running GFO, chaeto and a MarinePure brick. The information I am reading on carbon dosing says to base your dose off of current nitrate levels and monitor when they drop and adjust accordingly, but I am also reading that it is best to start when your levels are where you want them. I am not having any big algae issues but am having to clean the glass every other day and do have some buildup in my fuge.

I would like to keep my levels where they are and will ditch the chaeto if it does not make it. I have decided that I will probably use vinegar based on the articles and threads I have read on the options (vodka/vinegar/sugar/pellets/etc...).

What would be a good starting dose for my system if I have about 140 gallons of total volume? How can I tell what a good maintenance dose would be if my levels are already 0? I am planning on increasing my bioload and want to be sure I do not let the levels get out of hand so I want to start controlling it now rather than counting on the passive system I have now.

 

[JimWelsh]

As a vodka doser, I think the only reason to begin dosing carbon is because other methods of nitrate control are not working for you. It sounds as though you have a potential solution in search of a problem to solve. But, you do plan to add bioload, so.....

I'd suggest that you consider going ahead with the increased bioload and monitor nitrate. Once nitrate gets to a nice, measurable level, say somewhere between 1 - 2 PPM, then start very slowly dosing your preferred carbon source. I don't know how long it will take for the dosing to "kick in" when there is so little nitrate to begin with; my experience in bringing my tank down from 80+ PPM nitrate to zero a couple of years ago was that it took a few months before anything happened, and then, BOOM nitrate dropped dramatically over something like two weeks. Now, however, I can fine tune my nitrate level nicely with small adjustments to my vodka dose, and see the efect within a week or so. Hope that helps.

 

[CodyRVA]

This is a very complex and open ended discussion. I ran GFO and pellets with no fuge on a 46G bow front and stripped the water column of nutrients (also using just a small RO HOB skimmer). Since upgrading to an 80, i have a fuge, with chaeto, stopped running GFO, and i have a small CPR pellet reactor at maybe 30% capacity with great success. From what i've learned, start small and work up as needed. You may not even need to carbon dose. I would personally keep the chaeto if possible, I think it offers other benefits that GFO or Pellets do not. I would then introduce the other means of filtration if absolutely necessary, again starting small and working up.

 

[thewbell]

That sounds good and thank you for the advice. I will keep a close eye on it as I do not want to let my tank get to super high levels before taking action.

 

[Randy Holmes-Farley Verified Community Expert]

If you want to start organic carbon dosing, there's nothing wrong with picking a low dose and maintain that unless the nitrate gets higher or lower than you want.

That is how I initiated dosing since I too wanted to keep nitrate where it was and then slowly removed other methods (like macroalgae).

 

[ksed]

Randy,
Did you completely remove all the macroalgae ? I thought you still had some. Did carbon dosing work well enough that it didn't warrant the algae?

If you want to start organic carbon dosing, there's nothing wrong with picking a low dose and maintain that unless the nitrate gets higher or lower than you want.

That is how I initiated dosing since I too wanted to keep nitrate where it was and then slowly removed other methods (like macroalgae).

 

[hart24601]

Remember that carbon dosing isn't just for nutrient reduction. I dose carbon for feeding my sponges, dozen Hawaiian feather dusters plus smaller filter feeders!

 

[Randy Holmes-Farley Verified Community Expert]

Randy,
Did you completely remove all the macroalgae ? I thought you still had some. Did carbon dosing work well enough that it didn't warrant the algae?

I still had some, but far less and far less lighting for it. I didn't notice any problem with nutrients after changing, but I just took the tank down in the past couple of weeks. That said, I was not keeping a low nutrient tank, and my refugia had 1-2" of detritus mud on the bottom!