from Vodka to Vinegar

Just wanted to write a brief account of my most recent change in my carbon dosing method

I have for almost 12 months been dosing Vodka on a daily basis and due to fact that I started with 0 measurable levels of Nitrate and Phosphate according to Salifert test kits , never had to exceed 3 mils of vodka in my 75 gallons of saltwater


I wanted to automate the dosing ,using my bubble Magus doser, spare pump
3 mils of vodka dose not give you much in the way of options ( it can be dosed once in 24 hours @3 mils or twice in 24 hours @ 1.5 mils each dose)

whilst many people are bolus (adding all at once) even larger amounts of Vodka into their systems, I was of the opinion that spreading the dose in order to create a more consistent supply of the free carbons would be beneficial to my tank inhabitants

with the above in mind and after having done some research , I made the decision to gradually phase out the Vodka in favour of Vinegar

the vodka I was using was 40% ethanol by volume (ethanol being the carbon source)
the vinegar is 5% by volume acetate (acetate being the carbon source)

thus dosing vinegar to replace Vodka meant I had 8 mils of solution available to replace every 1 mil of Vodka reduced

thus my 3 mils of Vodka can and has been replaced by 24 mils of vinegar

method for change

for 1 week I dosed 2 mils of Vodka manually using syringe and hooked the vinegar bottle directly up to doser and dosed 8 mils
week 2 , I dosed 1 mil of Vodka and increased the dosage on the vinegar to 16 mils
week 3 , Vodka now out of the equation and 24 mils of vinegar is being dosed in 12 increments over each 24 hours

benefits
I had a small amount of cyno, which has now completely vanished, there are others in the hobby who are of the opinion that Vodka as a carbon source is more likely to fuel unwanted bacteria species such as cyno than vinegar is (basically ethanol is a better fuel for these pest bacteria than acetate is)
better control on amount being dosed, I now have more options in dosing patterns and dosing quantities ( I could have dropped from 3 mils to 2 mils on vodka using the doser but could not dose 2.5 mils etc - with vinegar I can drop by 4 mils or 6 mils etc and change smaller percentages being dosed )

aside from the cyno dissapearing
my skimmer is now producing more regularly , rather than peaks and troughs as it did before when triggered by the bolus dosing of vodka
my dosing is now as automated as my Calcium and Alkalinity supplements

No noticable negatives thus far ( no bacterial blooms, no pest bacteria, strings or fuzz )

vinegar and its effects on PH
having a PH probe and monitor has been a genuine asset during this changeover , 1 of the things that influenced my selection of Vodka was the fact I knew it had less immediate effect on PH than vinegar does

the reality when checking my own set up has been as follows
the introduction of 2 mils of vinegar every 2 hours, will cause the PH monitor to drop by 0.01 ph , but within 2 minutes the PH increases to the previous level again and continues to climb as it should during the day

my PH at 5 am on Saturday morning was 7.95, the vinegar dose took it to 7.94 (the lowest reading in 24 hours) within 3 minutes it was back to 7.95 and continued to climb with a 2 hourly 0.01 step backwards , but still peaked at 8.27 just before lights went out Saturday PM
I am certainly continuing to monitor the PH of the set up (easier with a probe than a test kit, that is for sure)
I am continually monitoring the tanks inhabitants and general conditions to see if this change of carbon source makes any further difference

I will update this thread as and when I have something new to share on this experience

Steve

 

Great info Steve, hope it continues to go as planned. I like the idea of a more steady introduction also.

 

The change in pH would've been my biggest concern (not a reef expert, but chem minor). Being that vinegar is a weak acid, something in the tank is neutralizing it. I'm not 100% sure if the components of your salt mixture are or your rockwork (likely a mixture of both, though buffers in salt mix are more likely being that they are already dissolved/aqueous). Granted, 8 mL is rather small but I'm curious what prolonged dosing will do. With all the pH buffering agents in salt mixes, I'm reasonably confident with water changes you'll never notice problems with pH.

 

Thanks John, the increased flexibility to fine tune the dosing is also a benefit

Thanks Jimmy
You are correct - tanks Alkalinity is naturally off setting the acid
although trying to dose 24 mils at one time would not be smart, which I could have done with 3 mils of Vinegar

I use an alkalinity supplement that also increases PH. Basically my home stays closed up most of the year as it is to hot
hence I need PH support in addition to Alkalinity supplement. (seachem reef buffer and Kent DKH supperbuffer - both these additives contribute Alk and increase PH

thus currently the Alk is being supplemented 12 times per 24 hours, and during alternate hours 2 mils of vinegar is being added

thus these 2 things are compensating for each other and cancelling each other out.

 

It's very interesting to me that even after your experiment you continue to dose your carbon source rather than switching to pellets. What is the reason for this? (Didn't the pellets win the carbon experiment you performed?)

 

great question Thatgrimguy and the answer is

I do not have a sump on my system which would mean HOB reactor and another pump in the DT
plus the liquid carbon dosing method seemed to be working out Ok Biofuel followed by Vodka and now vinegar
thus no real need or desire to change the method, I only changed the material / ingredient used to continue the method

Steve

 

Ahh makes sense. Do you dose Kalk? I have been reading a lot about combining Kalk and vinegar to be able to dose more kalk and as a side benefit dose the carbon source. That would stabilize the PH.

 

I am not currently dosing Kalk as I have the BM doser and dose 2 part

adding vinegar to Kalk in order to create super saturated Kalk - meaning you can dissolve almost 3 teaspoons into 1 gallon of water with 45 mils of vinegar instead of the normal 2 teaspoons per gallon into water without vinegar
is an option I have considered , but I think I would still have to 2 part dose anyway as my evaporation in this climate is minimal and do not believe I would be able to replenish utilisation with even saturated Kalwasser alone

 

I'm dosing two part as well. I did think about trying a super saturated Kalk. I know I would still need two part, but then I wouldn't have to fill my jugs nearly as often with the three of them going. But if you were to do it, would you be able to dose enough vinegar through this method to replace that doser?

 

not at current evap rates Thatgrimguy

I am losing about 1 - 1.5 litres per day at present - evap pretty constant all year for me
may get as high as 2 litres per day during really cool spells ( 7 C is coldest it gets here and that lasts a fortnight or so at worse)
which even with 45 mils to the gallon would give me 11 - 16 mils of vinegar and I am currently dosing 24 via the doser

Steve