My tank is at its best (i.e. no algae) when there is vigorous plant growth, which is usually a period from a few days after putting in new plants for about a week or 2. As my plants mature and get near the top of my 21" high tank, I'm not sure if growth slows or something else happens, but then the thread, hair and/or staghorn algaes start accumulating.

As an example, my recently purchased r. wallichii grew up to the top of the tank very quickly and is now collecting algae, the thread type, I believe. Am I right to assume at this point, that I need to prune in a way that keeps the plants growing vigorously? That is all I can come up with. I basically have been pruning very little, if at all.

Just pruning off a few of my ozelot swords' leaves a few days ago probably doubled the flow in my tank. I'm almost thinking the 2 ozelot swords are just too big of a plant for my 36x15x21 (50G) tank -- they are probably 14" high and almost go from the front to back of tank -- or I need to remove the plants around them, which I don't want to do.

Hi Ted,

About a year ago, I had a similar event with some vals in a 30 gal. Being convinced that it was a deficiency, I slowly increased my ferts and was able to stop this from happening. Like yours, it didn't happen until the plant reached the top. hope this helps

As the plants grow they choke off the easy circulation of water in the tank. Once they fill the tank from top to bottom you may have very limited circulation over much of the tank. That means where the plants are consuming the nutrients in the water, the water gets depleted of those nutrients, and with no circulation to speak of, it takes time for nutrients to diffuse back to the depleted areas, where it is being consumed faster than it arrives. That is how I understand it, anyway. The solution is to keep the plants pruned enough that water can easily circulate and add another source of water circulation, like a powerhead.

Thanks Chris and Hoppy ... this was helpful.

Chris, I'm still playing with the EI dosage. It's a trial and error thing at this point for me. I actually increased my dosage last week, but it didn't seem to help.

Hoppy, I think you hit one of my problems exactly. I recently put a powerhead in my tank, but I probably had too much of a mess in there for it to help much. I'm realizing when I see pics of others' tanks that mine gets way overcrowded in some areas -- I definitely need more open areas. Those ozelot swords are probably going to have to go. I should not have put them in the middle of my tank because they take over the whole think just about ... and they really block flow. I really dislike the idea of removing them both, so maybe just one at first.