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Crypt problems and Lighting for 2 foot deep tank

Subject: Crypt problems
 
> High nitrates?  Really?  I had never thought of this as a proble
> nitrates are food for the plants.  Do you know a scientific reas
> this, or is it based on your personal experience?  Finally, what
> should I try for, say 10-20ppm?

Aquatic plants much prefer ammonium as a food source.  Whether the 
nitrates themselves are a problem or whether they are a "marker" 
for the buildup of wastes products we cannot measure (and there 
are many) is not entirely clear.  But it has been observed by many 
people (including myself) that Crypts tend not to do well in tanks 
with high nitrate levels.  High nitrate is undesireable in a 
planted tank for other reasons as well... it tends to cause algae 
problems in the strong light of a planted tank.
 
> > If your UGF is old and dirty, this could be a 
> > cotributing factor as well. 
> 
> Dirty in what sense?  I do get pretty good clouds of dirt when I
> the gravel, such as by planting, but there isn't a ton of stuff 
> surface.  Also, observing the tank from beneath doesn't reveal a
> layer of black sludge, like I've heard of.

Dirty as in full of excess bacteria.  It is pretty widely believed 
that Crypt melt is cause by weakening the plants environmentally 
followed by the attack of certain bacteria.  You have to remember 
that Crypts do _not_ in general come from standing water.  They 
come from clean, fast flowing streams.  They do usually recover 
from these melts as long as the rhizome is undisturbed.
 
> > Crypts _do_ melt down sometimes, some 
> > species are worse about this than others.  But the fact that y
> > don't mention any species names makes me suspect that the Cryp
> > you are working with are the "generic" Crypts available from m
> > pet stores.  More often than not, these are a variety of C. 
> > wendtii (there are several) and are _very_ hardy.  They are al
> > usually emerse grown, and don't tend to melt when placed in a 
> > with good conditions.
> 
> The Crypts were sold as C. wendtii (2 stems) and C. cordata (2 s
> know that part of the problem is the continual disturbance that 
> plants are subjected to by the fish.  I have partly rectified th
> using a plug of plain rockwool to keep the fish at arm's (fin's 
> length.  

Hmmm.  Crypts do not grow as "stems".  They are small rosette 
plants connected by long runners.  Do you mean there are only two 
leaves on each plant? If so, these are _very_ young plants.  It 
can take a very long time for plants as small as these to become 
established. (up to a year or two before they begin to produce 
runners, up to several months before the even get roots firmly 
anchored in the substrate)  If they are disturbed during this 
period, either by the aquarist, or by fish in the tank, they will 
not take the disturbance well.  In fact, it can kill them 
completely.  As I said in my earlier post, THE MOST important 
factor to remember when growing Crypts is to provide STABLE, clean 
conditions.  If you can't do that, you're better off sticking  
with more tolerant plants.

>The 
> plant I think is a C. affinis is only a couple of day's in my po
> so I don't know if it will melt.  It is much bigger than the wen
> I've seen and does have the veins prominent on the top of the le
> which you mentioned.  Anyway, it has the "look" I was wanting, s
> going to run with it :-).

Don't kid yourself about the size of C. wendtii.  It can grow to 
about 18" tall.  Some of the people on the list have offsets of my 
stand of red C. wendtii.  They can tell you that this is not 
necessarily a small plant.  C. affinis, also, is very variable in 
size.  In _my_ tanks, that one stays quite small.  But I suspect 
that is because my water is rather harder than it prefers.  Color 
wise, it sounds that might, indeed, be what you have.  As always 
with Crypts, whether you can identify your specimen or not, enjoy 
it!  They are wonderful plants.

------------------------------
Subject: Lighting for 2 foot deep tank

Jack O'Leary posted:
 
> I have used standard 48" FL shoplights (4, for a total of 8 x 40
> watts of light) on my "optimum" 120 gallon, 2 ft. deep tank for 
> year.  Plant growth has been generally good, though some plants 
> prefer stronger light (Hygrophila sp., Mexican Oak Leaf) have no
> well as I had hoped.

<snip>
 
> So, normal or T-8 flourescents have worked quite well for undema
> plants in a 2 foot deep tank, and if you "roll your own" hood, t
> much cheaper than MHs.

Jack is being very modest.  This is a _gorgeous_ tank.  He does 
grow some plants that are generally considered to require stronger 
light. This tank won our very competitive B.A.S. Home Show 
"Natural" division last year, and I hate him 'cause he beat me. 
;-)

I know some people who do well with Hygro at much lower light 
levels than Jack uses, so I'm not sure that lack of light is the 
issue with this plant.  I think that everyone finds some plants 
that just don't do well in their tanks, no matter what.  (BTW, 
Jack, my Oak Leaf has finally settled in and seems to be doing 
well.  I suspect that the plants we both got just had a really 
hard time rverting back to submerged growth)

While it's possible that he'd do even better with MH lighting, I 
don't want to encourage him, or I'll _never_ win the title 
back!<g>

Karen Randall
Aquatic Gardeners Assoc.
Boston, MA