The more I learn the dumber I feel.

I've been battling this staghorn alage for maybe a decade now, sometimes it's not bad other times, holy cow, help. I've tried everything to get rid of it exccept bleaching everyhing and being a faithful follower of brother Tom Barr.

When I got seriously back into aquaria in the fall of 2004 my old nemesis, staghorn alage was still there making everything ugly. I sort of tried Tom's method, but after playing with test kits and jugs of white powedered chemicals for a month and getting nowhere I weant back to my uh, earlier "research" with noxious chemicals such as peroxide and algicide. Tests resumed, no significant progress ensued.

Then Tom posted a very folksy recipe on usenet and, modulo some screwing aorund with an iron test kit to get the iron levels right, I found it brainlessly easy to follow. I also decided if I don't have CO2 I should at least get some Excel to add carbon; the tendancy of it to hurt algae can't be a bad thing either.

The first time dosing IS a real pig if you want stock solutions and don't want to be forever dumping in powders from measuring spoons, I had to play with Chuck Gadd's calculator to figure out what to weigh out to make up a certain solution so I could simply dump 10 ml from a Tropica (TMG) bottle per 20 gallon tank; other tanks scaled accordingly and easily.

I've done this for one week, on series of identical 6 tanks. 5 of them I think are staghorn-free. One has it bad still. I'm not changing the water in that one; I want to keep it as a control. This tank gets only fertilizer and excel, no water changes.

The other 5 tanks get this treatment: excel per the label, and Tom's open-loop doing described in that article, saved here:

http://aquaria.net/articles/plants/barr-dose/

The 5 staghorn-free tanks are fine and look better already. The interesting thing is the 6th tank, with staghorn. I hoepd it would level off at least, but no, without a water change even the staghord is plain dying off.

In three days the one plant that had most of the algae (ludwigia glandulosus "Pereuensis") looked a little diferent. On the fourth day the staghorn had changed color, was now distinctly reddish and wispy. It's dead, Jim; I've seen enough chemically killed staghorn to know if it's gone from dark green-black erect branching to pinkish-red and wisty then it's dead, and tomorrow will be white. True enough, a day later, it's white and that Ludwigia plant now has half the staghorn it did a few days ago. Huh, how 'bout that?

I don't know what killed it, and to be sure there's still some in that tank, but I fear its days are numbered. Either the Excel killed it or perhaps now with proper nutrients and good light the plant just produced a lot of oxygen and killed the stuff off its leaf surfaces. Dunno, either way, or both perhaps.

I've seen staghorn get weak after a water change or two and turn light colored but I've never yet seen anything kill it this quickly short of a nasty chemical that does in the very least hold up plant growth for a while or worse, injure or outright kill, plants.