Vodka dosing question

jgvergo · Feb 20, 2018

I rebooted my tank recently and it has been running for 3 months. I'm dealing with some slimy green algae. I am considering vodka dosing to build up nitrifying bacteria that will outcompete the algae.

I read this article on vodka dosing, which seems pretty thorough. In the section on dosing instructions, the authors state "Test your system’s NO3 and PO4 levels. Do not dose if you do not know this!". They go on to lay out a procedure that is fundamentally tied to NO3 and PO4 reduction.

My issue is that my NO3 and PO4 are at zero (Red Sea and Salifert test kits, respectively). I'm guessing that the algae in my tank is consuming the NO3 and PO4 quite effectively.

I'm looking for suggestions on a procedure to follow for dosing under these conditions or should I simply stay away from dosing all together?

madweazl · Feb 20, 2018

In your case, carbon dosing may actually exacerbate the situation if it's cyanobacteria. You may find that dosing measurable levels of nitrate and phosphate will give the results you're looking for. Have any pictures of what you're trying to eradicate?

Richard the Reefer · Feb 20, 2018

Why not get some chaeto?

madweazl · Feb 20, 2018

Dick Dangle said:
Why not get some chaeto?

There may not be any nutrients for it to consume based on the test results. Harder to know since he isnt using a Hanna ULR for phosphates though.

jgvergo · Feb 20, 2018

madweazl said:
In your case, carbon dosing may actually exacerbate the situation if it's cyanobacteria. You may find that dosing measurable levels of nitrate and phosphate will give the results you're looking for. Have any pictures of what you're trying to eradicate?

Here is a short video. The best view of the algae is towards the end of the video

Randy Holmes-Farley · Feb 20, 2018

jgvergo said:
I rebooted my tank recently and it has been running for 3 months. I'm dealing with some slimy green algae. I am considering vodka dosing to build up nitrifying bacteria that will outcompete the algae.

I read this article on vodka dosing, which seems pretty thorough. In the section on dosing instructions, the authors state "Test your system’s NO3 and PO4 levels. Do not dose if you do not know this!". They go on to lay out a procedure that is fundamentally tied to NO3 and PO4 reduction.

My issue is that my NO3 and PO4 are at zero (Red Sea and Salifert test kits, respectively). I'm guessing that the algae in my tank is consuming the NO3 and PO4 quite effectively.

I'm looking for suggestions on a procedure to follow for dosing under these conditions or should I simply stay away from dosing all together?

You presumably mean denitrifying bacteria, not nitrifying bacteria, which convert ammonia into nitrate and do not necessarily need organics for that process.

jgvergo · Feb 20, 2018

Randy Holmes-Farley said:
You presumably mean denitrifying bacteria, not nitrifying bacteria, which convert ammonia into nitrate and do not necessarily need organics for that process.

+1 Randy

jgvergo · Feb 20, 2018

Dick Dangle said:
Why not get some chaeto?

Chaeto was my first attempted solution. It "melted" within a week. I even went out an bought lights for the sump. My fuge is now loaded with the algae.

jgvergo · Feb 20, 2018

madweazl said:
In your case, carbon dosing may actually exacerbate the situation if it's cyanobacteria. You may find that dosing measurable levels of nitrate and phosphate will give the results you're looking for. Have any pictures of what you're trying to eradicate?

I kinda think it's plain old green slimy algae.

jgvergo · Mar 4, 2018

Well, I figured I'd report back with some preliminary results. Here is the dosing schedule I used:
Days 1/2/3 0.4ml/day
Days 4/5/6 0.8ml/day
Days 9+ 1.2ml/day

After day 10, I had COMPLETE elimination of the slime in my DT and overflow, but is it still growing prolifically in my sump. I am now adding vodka to my ATO reservoir whenever I refill it. The current dosing rate is 1.2 ml/day. I'll cut back to 0.8 ml/day after a week and run it for two weeks at 0.8 ml/day. If the algae stays at bay, I'll cut back further to 0.4 ml/day and see if it works in the long term at that rate.

Sooooo happy with the results!! Thanks everyone...