vodka dosing ?

[troynel]

I have been vodka dosing for about 6 months now. My phosphates are always hovering around .02-.08. For example two weeks ago I tested PO4 (hannameter) and got a reading of .02 after upping my vodka dosage from 3.5ml to 4.0ml. Keep dosing at 4.0 then tested last week po4 and got a reading of .08. Did a water change at this point and upped the vodka to 4.2ml since. Tested po4 again this week and it reads .05.

My questions is I have green turf looking algae just on the barebottom of the tank and some red purple velvet looking algae on one rock and not much of it. Yes I realize algae will grow with some po4 present but I also dose MB7. Should i stop vodka for a bit and go heavier on mb7 or heavier on vodka. Ever since vodka dosing I have not been able to get my po4 level to 0.00.

Any advice?

[Nanook]

A couple things, the Hanna meter has accuracy of +/- 0.04 with each reading, so, one reading could be 0.00 and the next 0.04.

Also, since I spent about a year vodka dosing on my system, the phosphates were really never controlled without running GFO. Nitrates were reduced, but not phosphates.

[Nanook]

[moved]

[troynel]

200 bucks for a .04 + or -. Gezzzzz! Well my colors aren't what they should be and I have always blammed it on the phosphate. Also the green turf algae is something that started growing about 1 month ago and has gotten progressively worse. It's almost flourecent in color.

[bertoni]

You could try running a GFO, to see whether that helps. The algae are finding a phosphorus source somewhere. Other common approaches are better skimming and reduced feeding, although I think that skimmer (the ATB) gets good reviews.

[troynel]

yeah it's a hell of a skimmer as long as I have it dialed in right. I have been feeding a frozen food that might be contributing to the po4 but I can only cut back feeding so much since I have anthias. I usually feed 1 algea clip portion per 2 days and 1/2 a cube of food per day.

[Genetics]

I would recommend using some GFO like Nanook suggested for the phosphates and possibly upping the vodka dosage to help control the algae.

[bertoni]

That's not all that much food. I'd look at other solutions.

[troynel]

like?

[bertoni]

A GFO might help. Other people grow and harvest a macroalga to reduce nutrients. I'd also try using a Hach phosphate kit, if possible, to see how well the meter is doing. Its guaranteed accuracy in the low end is not very good, as has been noted. A Salifert kit might be fine, too.