Carbon dosing for ages with little progress. What's going on?

[Murraydar]

Hi guys, I think I need some opinions before I continue on with my carbon dosing.

So here's the deal. I have a chronic nitrate problem. Nitrates sitting around 30, phosphate is generally between .02 and .05 or so. I've been trying a few different methods of carbon dosing for around a year now to get my nitrates down, including biopellets, commercial products (nopox), and diy carbon. I'll discuss my current dosing regiment.

I dose a mixture of vodka and vinegar, 60% vinegar and 40% vodka, kinda like a diy nopox. My tank has a total of 91 gallons of water including sump. Its been about two months of dosing. I started low, and increased the dosage a bit everyday to where im at now. Im currently dosing a total of about 24ml of this mixture everyday, which in my opinion, is getting pretty high.

I know about the redfield ratio and made sure it's not impeding anything. In fact I dosed seachem phosphorus a while back because I had a fear I may have had bottomed out on po4. This wasn't the case. What happens is the carbon dosing actually reduces the po4 to proper levels. No issues there.

However, my nitrates isn't budging. I've done basically everything I could to try and get them down. Tried multiple bacteria additives per forum recommendations. I have a reef octopus 150 int skimmer, which should be plenty big for my setup. I clean it about once a day. I've been blowing out detritus from all the nooks and crannys. Tried with and without filter socks. All my other parameters are fine, fish seems healthy.

Do I keep upping my carbon dosing until something happens? Even at this high of a dose I have yet to see the 'bacteria bloom' that happens to alot of people. Don't know what else to do. Thanks for reading

[bertoni]

To Reef Central

That is a significant dose. Does the tank have a substrate that might be adding to the problem? I had to replace my crushed coral substrate for this reason. How much live rock is in the tank? What is the feeding rate?

[catman78]

How do your corals look?

[Belgian Anthias]

Originally Posted by Murraydar

Hi guys, I think I need some opinions before I continue on with my carbon dosing.

So here's the deal. I have a chronic nitrate problem. Nitrates sitting around 30, phosphate is generally between .02 and .05 or so. I've been trying a few different methods of carbon dosing for around a year now to get my nitrates down, including biopellets, commercial products (nopox), and diy carbon. I'll discuss my current dosing regiment.

I dose a mixture of vodka and vinegar, 60% vinegar and 40% vodka, kinda like a diy nopox. My tank has a total of 91 gallons of water including sump. Its been about two months of dosing. I started low, and increased the dosage a bit everyday to where im at now. Im currently dosing a total of about 24ml of this mixture everyday, which in my opinion, is getting pretty high.

I know about the redfield ratio and made sure it's not impeding anything. In fact I dosed seachem phosphorus a while back because I had a fear I may have had bottomed out on po4. This wasn't the case. What happens is the carbon dosing actually reduces the po4 to proper levels. No issues there.

However, my nitrates isn't budging. I've done basically everything I could to try and get them down. Tried multiple bacteria additives per forum recommendations. I have a reef octopus 150 int skimmer, which should be plenty big for my setup. I clean it about once a day. I've been blowing out detritus from all the nooks and crannys. Tried with and without filter socks. All my other parameters are fine, fish seems healthy.

Do I keep upping my carbon dosing until something happens? Even at this high of a dose I have yet to see the 'bacteria bloom' that happens to alot of people. Don't know what else to do. Thanks for reading

Carbon dosing does not remove a thing from the system. In fact it is the same as adding food as it produces protein (bacteria). The protein is consumed by organisms and most of it excreted as ammonia and some urea. All depends of the skimmer but we know that a skimmer removes max 35% of TOC present in the water column and is very selective in removing live bacteria. http://www.baharini.eu/baharini/doku...iwitafschuimer
A continues cycle is created from NO3 to NO3 as only a limited part of the nutrients added are actually removed. If nitrate concentration will not go down this means that no more as the total daily nitrate production is assimilated daily. The only thing one may do is increasing the doses, this if enough phosphate is available, otherwise increasing the doses will have no effect and create a bacterial bloom when phosphate becomes available, depleting DO.
What will finally happen with the biomass which is grown by regular carbon dosing? Carbon dosing is common practice in an aquaculture system but in these systems the produced biomass is harvested after a period of time.