Vinegar dosing making some acropora corals browner?

[KGV]

Did any of you with lots of different acropora species observed that dosing vinegar (100 ml, 5%, per day for a 800 liter tank) turns some acros browner? In particular some valida’s and my pearlberry Acro. I read that acetate can be used by some dinoflagellates and could increase their numbers and perhaps this causes browning? Note that most of acros are not affected.

 

[Randy Holmes-Farley]

Acetate can be used by most organisms in the tank, and that at least has the potential to increase the zoox in corals.

How did you arrive at that dose?

Maybe a lower dose is more appropriate.

 

[Miami Reef]

You can also switch to vodka. Zooxanthella can’t directly consume vodka.

 

[KGV]

Acetate can be used by most organisms in the tank, and that at least has the potential to increase the zoox in corals.

How did you arrive at that dose?

Maybe a lower dose is more appropriate.

I increases the dose until it matches my feeding so that NO3 is steady.

 

[KGV]

You can also switch to vodka. Zooxanthella can’t directly consume vodka.

That’s what I did, now it’d 50/50 acetate/ethanol.

 

[Randy Holmes-Farley]

I increases the dose until it matches my feeding so that NO3 is steady.

Over what time period? Days? Weeks? Months?

 

[Randy Holmes-Farley]

That’s what I did, now it’d 50/50 acetate/ethanol.

Did it help?

Does 50/50 mean equal volumes of equal organics dosed?

 

[KGV]

Over what time period? Days? Weeks? Months?

About 4-6 weeks.

 

[KGV]

Did it help?

Does 50/50 mean equal volumes of equal organics dosed?

Only started 3 days ago. 50/50 is equal moles of each.

 

[Randy Holmes-Farley]

OK, let's us know if that helps.

 

[Randy Holmes-Farley]

FWIW, ethanol packs more energy per mole than acetic acid, so you might find you want to scale back the dose if nitrate declines more.

 

[KGV]

Since a month, I have switched now from only vinegar dosing (100 ml 5% /day) to 20 ml/day vinegar and 10 ml ethanol 40%. My acropora are overall doing better now and alk consumption is going up again. The main observable difference is that with vinegar, I had excessive slime on the surfaces, very noticeable on the glass. It looks like a white film that many will be familiar with. With the new vinegar/ethanol combo that is not the case anymore. It is still very powerful to keep NO3 stable.

 

[Randy Holmes-Farley]

Since a month, I have switched now from only vinegar dosing (100 ml 5% /day) to 20 ml/day vinegar and 10 ml ethanol 40%. My acropora are overall doing better now and alk consumption is going up again. The main observable difference is that with vinegar, I had excessive slime on the surfaces, very noticeable on the glass. It looks like a white film that many will be familiar with. With the new vinegar/ethanol combo that is not the case anymore. It is still very powerful to keep NO3 stable.

Sounds like a reasonable approach. There are a vast number of different bacteria that may take hold, and different organics may lead to different species dominating. Some may be visible and hence problematic, and others not so much. When visible bacteria are a problem, switching organics is a good thing to try.

 

[Reefahholic]

I’ve had great results with Vodka. Currently doing a 40% Vodka + 60% Vinegar mix. So far…no noticeable differences yet. Alk is dropping slightly, but not by much.

 

[KGV]

For completeness, when I started dosing vinegar (30 ml, 5% in a 800 L tank), I saw some acros spring to life after being dormant for a long time. With that I mean, they got growth tips, their base got the pale growth edges, and better PE. I was super happy about that thinking that I found the missing factor for these few difficult acros (carbon?). However, in my excitement I increased in just a few week to 100 ml 5% daily, and then things went south with browning and reduction in alk consumption.