May 18, 2008

In my last journal post I said that I’d keep my hands out of the tank until the end of the month, when I passed the one-year mark for the tank. Well, those intentions were great… but I could not help myself.

Most of the stem plants were at the water’s surface, and I don’t want them to get too “leggy”. I’m not a good aquascaper, but if I have to hang on to stem plants to keep this tank healthy, I’d at least like them to be bushy and thick. So they were getting a bit too tall and I cut them.

Because I’ve been fighting excessive Green Dust Algae (GDA) on the tank walls for a number of months, and because it has been MUCH better in the last month or so, I’m worried about pulling too much plant mass out of the tank. So I took metal weights and wrapped them around the tops of the stems I trimmed, and sunk them back into the tank. So hopefully they’ll keep growing and plant mass will not be too adversely impacted by the trimming.

In the pic you can see that the Ludwigia repens to the left is not doing well at all. When I let it grow to the surface it is thrilled. But even nine inches lower than the surface and it starts to really suffer. Now, where I have it growing is not directly under the metal halides. This plant needs high light to thrive. But I’m hard pressed to believe that being 18″ from a 150 watt HQI lamp is not enough light to thrive. I just don’t buy it. Instead I think that when it gets really, really close to the light that the photosynthetic rate that results somehow gets beyond what ever else is holding it back.

I can’t be sure, but I suspect the problem is temperature. My temps fluctuate from about 81.5 to 83.5 during the day. And Ludwidgia - a native of North America - is a cool water plant. But supposedly it can tolerate warmer water. This is kind of my test.

Anyway… the some of the other stem plants I inserted to help with the GDA - Wisteria (Hygrophila difformis) and Green Temple (Hygrophilia corymbosa) - seem to be dealing with heat just fine. Since I’m personally fond of Ludwigia’s, I’d be really tickled if this gets healthy too.