Carbon (vodka) dosing if NO3 and PO4 read zero

I want to dose a carbon source to increase bacterial count, but my test kits read NO3 and PO4 as zero for some reason. I've tried two different kits and both give me no readings on nitrates and phosphates.

So how should I proceed to dose carbon (probably in the form of vodka)? My tank is a 176 gallon reef.

 

in my opinion its risky in the first place and really requires experiance and hawk like monitoring. But it sounds like you have no need to consider it -- so I say no to your question

 

Aside from NO3 and PO4, what should I be monitoring for? I've been in this hobby for 20+ years, so experience (and understanding how to observe my livestock) isn't an issue

I still have green turf algae and cyano present in the tank, so readings do not appear to accurately reflect the nutrient level in my tank. But more than anything else, I want to boost bacterial count.

 

Readings don't reflect a count, they reflect what is available. If uptake of N and P are at the same rate as production what is left is zero. You can have a tank full of algae and have zero redaings..... obviously there is N and P being produced.

What kit are you using for PO4? If it isn't Tunze or Merck, then I can pretty much tell you you are not at zero.

Dosing carbon sources certainly works and is proven.... but now adays... liqiuid dosing has far greater risks and is much more PITA compared to solid dosing. Get yourself a reactor and some bio pellets and be done with it.

 

I'm using Salifert and LaMotte. I realize my nutrients aren't zero, but it's hard to administer dosage without knowing these values.

I'll take a look into the pellets. I was thinking about manual dosing as I would have more control over dosages; I've read some "bacterial bloom" horror stories with pellets. Do you have a recommendation on which pellets to use? And can I run them in my phosban 550 if I mod it with a screen, or do I have to purchase another dedicated reactor?

 

Hi Leonard

I am currently vodka dosing with 0 N and P and had 0, N and P when I started

use the same methodology as described by Genetics and Stony Corals
in Vodka Distilled

things to watch for as you gradually increase the dosing based on above plan are

positive signs that indicate all is well
corals maintain coloration

a reduction in the speed at which algae develops

less frequent need to clean glass

negative signs
cyno bacteria - which being a bacteria is just as likely to be fueled by the carbon source

white stringy bacteria - looks like a white fuzzy beard - again the carbon source can fuel bacteria other than the positive ones we are trying to encourage

corals fading in color - NB increased supplementing with aminos has proven effective in my case at reversing this aspect

the above negative signs are a signal to either reduce Vodka dosing by half of the current level or stop completely until these situations have been dealt with

Steve

 

Tunze and Merck are high resolution kits. Everything else is low resolution and are only good for gross measurements. The Hanna checker is reported as good high res readings.... but I sort of don't like it just for numbers alone.... it's +- margin is larger than what is good for our tanks... like .2.... but lot's of folks have cross checked them against good kits and trust their reliability. I had a Merck kit... but after I saw my number I didn't really care. I ran GFO and then went to pellets and just didn't care what the actual number was.. I was confident it was good for my reef.

Warner Marine Ecobak. I trust WM and they just became a sponsor here. His pellets are not the same relabeled stuff they is out there. He makes them and it's proprietary.

Pretty much any media reactor with a screen will do. Real simple. No maintenance. No worries about over dosing or bacteria blooms. Heck you can even run it passive in a media bag in the sump if you want.

 

Before dosing carbon sources, make sure your skimmer is up for the challenge. Ive seen countless disasters from using undersized skimmers.

Have you tried manually removing your GHA and cyano? Using GFO and changing it out when it has been exhausted is key to it's success. Testing the water output until it starts to show PO4's, then replacing the media.

What kinds of livestock do you have? If you are heavily stocked, then carbon dosing may be your best bet? If you aren't and the issues are from using water with high TDS, or from years of heavy feedings, then you may want to consider other options.

 

Tank is a 176g. I run a Vertex Alpha 200 skimmer with a 2 gallon collection container. I think it's up to the task.

My cyano is very limited, and it only really grows directly over decaying matter (like dying algae) ... very localized and not a concern for me. I don't have GHA, but I have this brillo-like green algae that isn't quite Chaeto (at least not the Chaeto I've had in year's past).

It's currently stocked with a black tang, an arcuatus angel, a borb anthias, a big male Rhomboid wrasse (looking for a female), 6 flavoguttatus anthias, a dozen tiny red dot cardinals, a tiny goby and a small sailfin blenny.

 

Thanks Steve. I'll watch carefully for the things you listed.