Re: Aquatic Plants Digest V2 #303

>>I planted E. tennellus in my 55, and true to form it took off and made a
>>very attractive carpet in the foreground.  About a month ago, growth
>>stopped and now many of the leaves are transparent.  Nothing has changed
>>that I am aware of - weekly water changes 10-20%, lights on a timer
>>12H/day, 2 40W bulbs 1 full spectrum and 1 warm spectrum (they are about
>>5 mo. old), temp 78F, pH 7.2, inconsistent addition of FerroVit, regular
>>gravel no addition to substrate.  Any suggestions to stop the trend and
>>get back to growth and runners?
>..................<rest snipped>.......................
>When you say that many of the leaves of the E. tenellus are transparent, I
>assume that you mean the older leaves, and that they are dying back, and
>you are seeing just the dead veins with the tissue in between gone.
>Someone else has suggested potassium deficiency, and that is a good
>possibility.  Postassium deficiency causes older leaves to develop small
>dead spots that spread and become more numerous until the entire leaf is


I've seen translucent leaves on E. tenellus numerous times in my 120 gallon,
although in my case it seems as though the plants continue to grow, and both
new and old leaves exhibit color loss.  It also seems to differ from what
Paul has described in that the color loss is pretty even (no dead spots) and
that there is tissue between the veins, but is either thinner than normal or
lacking color.

Most of the times I've seen this, the CO2 system is found to have stopped (I
can't believe how much trouble I've had keeping this system going), and the
plants respond well after a few days of  CO2 injection. In a couple of
instances, though, the CO2 appeared to be fine, but the automatic fish
feeder had "failed"; again, restoring the equipment led to improvement of
the E. tenellus.  I can't tell for certain whether the formerly translucent
leaves regain color and vitality or are simply replaced by newer, healthier
leaves - probably some of each.