Carbon Dosing dos and don'ts

[Treefer32]

So, I want this to be less about what to not do and what is the right way to do things and maybe a couple consequences.

I've been vodka dosing (Carbon Source for bacteria) for about 6 months on my 340 gallon mixed reef to primarily control nitrates. Hoping for some phosphate control mixed in as well. I was up to 30 ml per day of vodka and it seemed that my nitrates stopped increasing and decreased / remained stable in the low 20s ppm. (Hanna Nitrate tester).

7 Weeks ago I added a pellet reactor thinking that would be even less maintenance and cheaper than vodka. And slowly, over the 7 weeks decreased my Vodka dosing down to around 10 ml per day. Reducing by 1-2 ml per week.

As I did this my Nitrates went from being managed in the 19-23 ppm area to 40-50 ppm. My phosphates went from being managed in the .04 to .09 ppm area to .40 ppm. 2 40-50% water changes in the 6 months of vodka dosing. (1 every 3 months or so hoping to decrease to 1 every 6 months).

So, that said. I realized the Pellet Reactor isn't doing what I would like it to do and need to raise my vodka dosing somewhat rapidly to get nitrates back under control. I also am dosing Micro Bacter Clean (claims it contains live bacterial strains and according to the vendor, the pellet reactor needs to be seeded with P&N Consuming Bacteria. I don't believe this, but, MB Clean seemed the best option for an old tank to add bacterial diversity.)

So, that said. Assuming the Pellet reactor will not do enough.. Ugg.. Not sure I'll even keep it operational when the pellets are gone. I may change it to an Aqua Char rector or something.

I plan to increase my vodka dosing back to meeting what my tank needs. Probably a 10:1 up to 15:1 ratio of ml of vodka to water volume. 340 gallon so, around 34 - 51 ml per day of vodka. I'm currently up to 15 ml per day.

All the carbon dosing recipes say to only increase by .5 ml per week. So, if dosing 15 ml per day. Then next week 15.5 ml per day then 2 weeks out 16 ml per day and so on.

Can I double my dosing from 15 ml to 30 ml per day within say a 7 day period? Increasing by 2 ml per day or something like that?

I understand the need to go much slower for 100 gallon systems or less. And I do notice a PH decrease. I was at 8.32 per day and now with the increased dosing my the high my ph gets to is around 8.12 and at night the low is around 8.05. Both well within acceptable areas.

In shot, I just need to know what are the consequences (and limits) of increasing vodka dosing per day. Or is it a safety net and since I've already been dosing for a while, within a week I could be back up to the 30-40 ml I was dosing a couple months ago?

 

[Randy Holmes-Farley]

IMO, the slow ramp up in doses that some articles suggest is unnecessarily conservative, and if dosing something like vinegar, I do not see the need for a ramp.

 

[Treefer32]

I could see maybe, starting from no carbon dosing ever, then ramping up more slowly just to get initial populations going, but, if the system has seen carbon dosing and even minimal levels maintained. I didn't see what would be the need for caution other than overdosing.

 

[MexiReefer]

I have dosing vinegar (around 20 ml daily) in my RedSea reefer 175 for over 8 months now, and I experienced a los of improvement in the corals. I can't say that it is realaeted to nutrients levels, since I saw not much of a decrease of NO3 or PO4, but something else happended.

 

[Treefer32]

I have dosing vinegar (around 20 ml daily) in my RedSea reefer 175 for over 8 months now, and I experienced a los of improvement in the corals. I can't say that it is realaeted to nutrients levels, since I saw not much of a decrease of NO3 or PO4, but something else happended.

I lost an gold hammer, but the orange hammer right next to (1 inch away or less) is growing new heads and doing great. I think The tissue lost started to nitrates and phosphates being too high. Sudden changes in nitrates and phosphates can cause tissue loss as well, so it's a balancing act of getting things out of the danger zone, at the same time, making sure that more things don't become too endangered due to the solution. Phosphates at .5 caused many of my corals to start losing flesh, once I got it under .4 the flesh started growing back... Go figure. . .

 

[Miami Reef]

IMO, the slow ramp up in doses that some articles suggest is unnecessarily conservative, and if dosing do ring like vinegar, I do not see the need for a ramp.

Hi Randy,

When you say no need for a ramp, can you explain how fast I can go?

I’m dosing 50mL spread in my 260 gallon per day and I’m not seeing any bacterial growth whatsoever. Nitrates are not moving either. How did you settle on your dose?

 

[Randy Holmes-Farley]

Hi Randy,

When you say no need for a ramp, can you explain how fast I can go?

I’m dosing 50mL spread in my 260 gallon per day and I’m not seeing any bacterial growth whatsoever. Nitrates are not moving either. How did you settle on your dose?

Over a long period of time (months or years) I experimented with very high and low doses. At the high end, the water became hazy and some creatures did not look optimal.

what is the nitrate level now and how long have you dosed 50 mL?

I certainly see no reason you cannot try double that if you’ve been there a while.

 

[Miami Reef]

Over a long period of time (months or years) I experimented with very high and low doses. At the high end, the water became hazy and some creatures did not look optimal.

what is the nitrate level now and how long have you dosed 50 mL?

I certainly see no reason you cannot try double that if you’ve been there a while.

Nitrates testing at 10ppm. Phosphates 0.04ppm. The main reason for dosing vinegar is not for nitrates - I just want to see some evidence of white bacterial growth in the tank. I’ve been dosing 50mL for 2-3 weeks.

 

[Treefer32]

I'm around 50 ml per day and I get fluctuations in my nitrates. Not sure why. But they've dropped from 50 down to 17.9 right now. I backed off on dosing down to 40 ml per day and they started rising within a week.

Generally, I try to do a week between dosing as generally I've found that any significant changes in nitrates take that long. I've not tracked it with scientific precision to say changes don't happen sooner.

I agree with Randy, that high levels of dosing brought my nitrates down to 3 for a couple weeks. My water turned white / cloudy, my hammers all stayed closed, and corals changed color. They weren't liking the bacterial conditions. I backed off on dosing and it got less cloudy and within a few days the nitrates went from 3 to 17.9. So, I don't know the answer. Only that changes in dosing regimen can take 3-7 days to register in the display from my experience.

I go with 7 days between testing to have consistency. In no way proves that it takes 7 days.

 

[Treefer32]

I'm around 50 ml per day and I get fluctuations in my nitrates. Not sure why. But they've dropped from 50 down to 17.9 right now. I backed off on dosing down to 40 ml per day and they started rising within a week.

Generally, I try to do a week between dosing as generally I've found that any significant changes in nitrates take that long. I've not tracked it with scientific precision to say changes don't happen sooner.

I agree with Randy, that high levels of dosing brought my nitrates down to 3 for a couple weeks. My water turned white / cloudy, my hammers all stayed closed, and corals changed color. They weren't liking the bacterial conditions. I backed off on dosing and it got less cloudy and within a few days the nitrates went from 3 to 17.9. So, I don't know the answer. Only that changes in dosing regimen can take 3-7 days to register in the display from my experience.

I go with 7 days between testing to have consistency. In no way proves that it takes 7 days.

I just saw you're dosing vinegar. I believe that Randy indicated Vodka is 8 times stronger than Vinegar. So, the equivalent to what I'm dosing would be 50 ml per day vodka * 8 = 400 ml of vinegar. I have a 340 gallon system.

So, 50 ml of Vinegar would not be a lot of carbon dosing. You probably won't see visible signs of bacteria if that's all your dosing in 260 gallons.

 

[Randy Holmes-Farley]

Nitrates testing at 10ppm. Phosphates 0.04ppm. The main reason for dosing vinegar is not for nitrates - I just want to see some evidence of white bacterial growth in the tank. I’ve been dosing 50mL for 2-3 weeks.

Id be wary of going higher for fear of bottoming out nitrate.

 

[Randy Holmes-Farley]

I just saw you're dosing vinegar. I believe that Randy indicated Vodka is 8 times stronger than Vinegar. So, the equivalent to what I'm dosing would be 50 ml per day vodka * 8 = 400 ml of vinegar. I have a 340 gallon system.

So, 50 ml of Vinegar would not be a lot of carbon dosing. You probably won't see visible signs of bacteria if that's all your dosing in 260 gallons.

In my 120 display with about 300 gallons total, 400 mL per day of 5% acidity vinegar was clearly too much. My regular dose was about 110 mL per day.

 

[Dan_P]

In my 120 display with about 300 gallons total, 400 mL per day of 5% acidity vinegar was clearly too much. My regular dose was about 110 mL per day.

For my system, I found 1 mL vinegar per gallon of aquarium water produced visible white slime. Observed this twice.

Once the nitrate declined to the point I wanted, the dose was lowered from 1mL/gallon until the nitrate began to increase. Then I increased the dose a bit to stabilize the nitrate concentration.

 

[ScionFRSguy]

Using too much carbon can be harmful to your tank. It's hard to figure out exactly how much carbon your tank needs so start slow. I use light carbon and switch they out frequently. I use about a 1/3 of the amount recommended every 4 or 5 days.

 

[Randy Holmes-Farley]

Using too much carbon can be harmful to your tank. It's hard to figure out exactly how much carbon your tank needs so start slow. I use light carbon and switch they out frequently. I use about a 1/3 of the amount recommended every 4 or 5 days.

You sound like you are talking about something different: granulated activated carbon, not organic carbon dosing.

 

[ScionFRSguy]

You sound like you are talking about something different: granulated activated carbon, not organic carbon dosing.

Yes sir! Granulated activated carbon

 

[Saltyanimals]

Yes sir! Granulated activated carbon

Different conversation. =) Granulated activate carbon (GAC) the black coal looking stuff vs this discussion on "carbon dosing" using vodka, vinegar or sugar.

Hey @Treefer32 . You mentioned weekly dosing vs daily. That's the direction I'm trying to head myself as I don't want to use a doser for daily dosing and rather do all my dosing weekly. My theory is similar to yours that my NO3/PO4 shouldn't swing that much to be harmful to a tank. Even SPS. Care to share on your weekly dosing experience?

 

[Treefer32]

Different conversation. =) Granulated activate carbon (GAC) the black coal looking stuff vs this discussion on "carbon dosing" using vodka, vinegar or sugar.

Hey @Treefer32 . You mentioned weekly dosing vs daily. That's the direction I'm trying to head myself as I don't want to use a doser for daily dosing and rather do all my dosing weekly. My theory is similar to yours that my NO3/PO4 shouldn't swing that much to be harmful to a tank. Even SPS. Care to share on your weekly dosing experience?

Depends on size of tank and how much you're dosing. I'm actually dosing daily what many would be dosing weekly. So, yes a weekly dose should work. I'm dosing around 40 ml per day. Was up to 80 ml per day. I just am using a basic BRS doser with my apex and dosing 4 timers a day around 10 ml per time. Without skimmer ph dropped to 7.83 at night. With skimmer, ph hits around 8.01 at night and 8.1 during the day.

I am dosing baked baking soda for alk, which is supposed to raise ph as well.