I have a low tech 55g and none of my plants are showing the obvious signs of deficiency like yellow leaves, melting, or holes in leaves. But...I do have 4 types of algae: BBA, GDA, Spot, and Fuzz or Hair. None of these are really bad, and the only one which seems to have gotten worse since I've stabilized my tank is the hair algae.

I feel I need some tweaking to be done to my dosing, but how does a person know where to begin? I was under the impression that since my plants looked fine, that any changes needed were probably a reduction of some kind as I've read that hair algae can be caused by too much iron in the water. I was gonna half the flourish dosing, but the more I read, the more complicated it seems. How do I know if I need an increase or decrease and of what?

I have 1wpg and am dosing weekly:
1/4 tsp KNO3
1/8 tsp KH2PO4
flourish recommended dosing

Also, could my relatively new flourite sand substrate be causing too much iron in the water if rustled up or is it only possible with liquid ferts?

Trivr

If the tank is still cycling (due to a new substrate) you will have more algae issues than not......

You may want to do a couple of 50% water changes every other day or more if it is a new substrate if it is in fact cycling...........

I would say ammonia is more the issue than iron if the substrate is new..........

Flourite doesn't leach iron, as far as I know. It is an inert substrate made from a clay that has a reasonably high iron content, so the iron is tied up in the crystal structure of the clay. I'm not sure that plant roots can access that iron either.

Gerry - I hadn't considered the substrate a possibility as I only changed 2/3 of tank about three weeks ago, but nonetheless, I rechecked ammonia with two different tubes and found none.

Vaughn - If iron rich flourite doesn't leach into water and it's correct that excess iron contributes to hair algae, than I guess reducing flourish would be a good starting point to see what happens. Correct? And if this liquid fertilizer is contributing to algae, then am I safe to assume a third to half reduction will not create any deficiencies in my plants? Also, what evidence do I look for to judge if my macros should be increased or decreased?

Are these questions impossible to answer, and have I run square into the *art* part of this hobby where the uniqueness of each tank requires trial and error and a feel for what's needed?

I'm following the 'non co2 methods' for this tank and feel I'm in the ballpark as none of this algae is out of control as it had been previously but I'm excited and determined to reduce it even more so I can finally declare success!

I don't believe that excess iron contributes to hair algae growth. I have always used CSM+B+Fe as a trace mix. That is regular CSM+B with twice as much iron. (I have always used it because a pound of it lasts for a very long time in the size tanks I have been using.) I had a brief bout with hair algae in a 29 gallon tank right after it was set up, when I couldn't get the concentration of CO2 in the water to be where it belonged. But, none since. If iron was a contributer to the hair algae problem I should have been in a constant war with hair algae.

I haven't been doing a "non CO2" tank, except for a 10 gallon tank I just experiment with, so I have too little experience with that to comment on.

Sorry Vaughn,

I had again read Dusko's algae article after reading your post. It was thread algae with links to iron, not hair or fuzz. I've read so much trying to get ahold of this, got my info confused. I have fuzz algae growing on my anacharis and all it states is that these plants may be suffering from some kind of deficiency...so that's where I'm at...how do you know?

Anyway...can always count on you to answer my posts, thanks for your help. I'll eventually figure it out as I've already learned alot and made good progress with the planted tank in the four months or so that I've been at it thanks to this site.

Trivr