Dosing sugar chart?

[Miami Reef]

I am trying to make an experiment comparing bacterial growth with different carbon sources and I need to dose equal amounts of carbon with each trial.

I am going to use vinegar (5%), vodka 80% proof, and 100% dextrose (glucose).

I know vodka has 8x more carbon than vinegar in a volume basis, so if I’m trying to dose 10mL of vodka, I’d need 80mL of vinegar to get equal amounts of carbon.

How do I figure out how much sugar I need to have the same amount of carbon as vodka and vinegar? I know this question is pretty vague, because I didn’t mention how much molecules of carbon I’m even targeting.

@Randy Holmes-Farley

 

[Miami Reef]

Maybe there’s some sort of conversion factor with vinegar and dextrose (for example, .1g of dextrose has equal amount of carbon as 10mL of vinegar) etc?

 

[taricha]

I'd work in grams (or mg) of carbon.
(Hopefully someone will correct if I messed this up)

Vodka, 80 proof. 40% alcohol by volume. Density of ethanol 0.789 g/ml. Ethanol 52.2% carbon.
So 1. 00 ml of vodka...
1.00 * 0.40 * 0.789 * .522 = .165 grams carbon

Glucose is 40.0% carbon, so for 1 gram of glucose...
1.00 * 0.400 = 0.400 grams carbon.

 

[Miami Reef]

@taricha

First, thank you,

So here’s what I’m proposing:

0.413g of glucose
1mL vodka
8mL of vinegar


Just check my math on this one. Am I getting the same amount of carbon?

I will do 2 trials, one with lower carbon, and one with higher carbon in ratio with tank water.

 

[taricha]

0.413g glucose, 1.00 mL vodka, and 8.2 mL vinegar should all have about 0.165 g Carbon I think.

5mg/L Carbon is enough to deplete essentially all the O2, but you could go much higher, like 50 or 100mg/L carbon if you repeatedly stirred or aerated the containers.

anaerobic processes probably aren't super relevant to the bulk of a carbon dose in the hobby, so I wouldn't go too high without aeration.

 

[Dan_P]

I am trying to make an experiment comparing bacterial growth with different carbon sources and I need to dose equal amounts of carbon with each trial.

I am going to use vinegar (5%), vodka 80% proof, and 100% dextrose (glucose).

I know vodka has 8x more carbon than vinegar in a volume basis, so if I’m trying to dose 10mL of vodka, I’d need 80mL of vinegar to get equal amounts of carbon.

How do I figure out how much sugar I need to have the same amount of carbon as vodka and vinegar? I know this question is pretty vague, because I didn’t mention how much molecules of carbon I’m even targeting.

@Randy Holmes-Farley

A short cut: Glucose is three acetic acids worth of carbon

 

[Randy Holmes-Farley Verified Community Expert]

I don’t think there is any single correct way to compare doses. The chemicals have different amounts of usable energy per gram or per carbon, etc.

I’d just compare them by weight of organic matter.

 

[Miami Reef]

I don’t think there is any single correct way to compare doses. The chemicals have different amounts of usable energy per gram or per carbon, etc.

I’d just compare them by weight of organic matter.

How can I compare by weight of organic matter?

 

[Randy Holmes-Farley Verified Community Expert]

How can I compare by weight of organic matter?

Solid sugars = 100%,
5% acidity vinegar is 5% organic by weight.
80 proof vodka is 40% by weight.

So equal weight is 1 gram sugar, 20 grams vinegar or 2.5 g vodka

 

[Miami Reef]

Solid sugars = 100%,
5% acidity vinegar is 5% organic by weight.
80 proof vodka is 40% by weight.

So equal weight is 1 gram sugar, 20 grams vinegar or 2.5 g vodka

I’m not sure how you got 20g vinegar from 5% nor the vodka 40% being 2.5g.

 

[Sean Clark]

If you boil 1 part dextrose in 1 part water for 5 minutes it will break down into a single simple suger and will be more easily processed by small organisms. Just to add another layer of complexity to your thought experiment.

 

[taricha]

I’m not sure how you got 20g vinegar from 5% nor the vodka 40% being 2.5g

20g * 5% = 1g

2.5g * 40% = 1g

 

[Miami Reef]

Okay, I’m back.

These cups were thoroughly rinsed in tap water. They were allowed to completely dry. I then dunked the cups numerous amount of times in my sump before making a final fill.

FYI My sump has a skimmer with ozone being used (carbon on the output). I filled the cups pretty much near the skimmer. Not sure if ozone would affect my results, but all the cups have the same water.

I made sure my scale was calibrated. It has an accuracy 0.1g.

@Randy Holmes-Farley @taricha

I am mainly wanting to see the bacterial structures. Do you think aerating these cups would provide useful benefit, or will aerating the cups break apart the bacterial structures?

Also, Randy, can you merge this thread into this one: https://www.reef2reef.com/threads/bacterial-growth-with-different-carbon-sources-experiment.943787/

 

[taricha]

To see the structures that the bacteria will produce it's helpful to go to higher carbon amounts, and to do so aerobically, aeration or at least stirring a few times a day is necessary. Bacteria will form films and flocs regardless.

When I did this, I was around 40mg/L Carbon. Ethanol grew way more visible gelatinous material than the other Carbon sources I tried. No idea if that'll be repeatable.