Re: lawn plants-lighting and sword plants-nutrition

Karen Randall writes
>  Steve,
>  >> Yeah, but that's good because you don't want the lawn to be so fast
> growing that it takes over or chokes out the other plants. <<
>  Most of the best "lawn" type plants need quite a bit of light.  

Some of the best "lawn" plants are the chain swords.  There are 6 or 7 
different Echinodorus species/varieties.  One type that I keep (E. 
tenellus var tenellus) actually grows better for me in dim lighting. 
(e.g. a 30 gallon (36" wide) with a 20 w Triton).  With brighter 
lighting, it also gets smaller. This variety is the one with 1-2mm leaves 
that I refer to as pygmy chain sword.

> This limits
> them to a large extent to the open areas in the front of the tank.  

These pygmy chains get the tallest and pile up in the corners of tank.

> I haven't
> seen and signs of any of the common "lawn" plants choking out other plants.

In my 70g tank with only 2 40w bulbs, no CO2 and peat substrate, my chain 
swords are extemely dense; more dense than I prefer.
Consequently, they *ARE* choking out other plants and have actually 
choked out each other.  I started with 3 varieties (E. tenellus var. 
tenellus;  E. tenellus var. parvulus, the 'narrow leaf chain sword' and E. 
quadricostatus, the 'wide leaf chain sword') together with several 
crypts, among other plants. I had the swords nicely 
separated, the the smallest ones in the front, etc.  The narrow leaf are 
now dominant, and I have to periodically thin them out so that I can see 
the crypts. If I spent more time with the tank, I could have kept thinks 
under better control.

>  >> We have to think about what plant LIKE to grow together too and I
> understand swords and esp. Crypts prefer their own kinds. <<
>  I have not found this piece of folk lore to hold true in any of the tanks I
> have.  I grow Crypts and Swords with all kinds of other plants.

***this is a great topic on which to get some discussion started. I would 
like to come back to this another time***

> From: Erik Olson <olson at phys_washington.edu>
> Date: Sat, 13 May 1995 08:46:02 -0700 (PDT)
> Subject: Re: Aquatic Plants Digest V1 #67
> > From: Mark Wickersham <mwickers at minerva_cis.yale.edu>
> > Date: Fri, 12 May 1995 22:44:01 -0400 (EDT)
> > Subject: More on E.tenellus; [blank]-Glo bulbs?
> > 
> > 1) I read in B. James that lighting for e.tenellus is "Not critical" (one 
> > of the least descriptive terms he uses), but in several other references 
> > in a local shop I read that, as a "lawn" plant, it requires "strong 
> > illumination."  My 24", 20W Biolume does well for Java Fern and, I hope, 
> > c.wendtii and a.nana, but will that be enough for e.tenellus?
> I don't think they'll be happy with one tube, Biolume or not.  For it to 
> propagate well, it should have 2-4 tubes above a modestly-deep tank (18").

Unfortunately, E. tenellus is not sufficient description. I think Barry's 
picture shows the tenellus var. tenellus.  Although lighting is not 
critical, it will change color with brighter light, and become reddish.
It may also become smaller.

 > > From: fidder at drmail_dr.att.com > Date: Sat, 13 May 95 21:03:04 MDT
> Subject: Problem with Amazon Sword
> Hi,  
> I have had a complete high tech 180 gal plant tank up and running for
> about 3 months now and have had some mixed results. 


> The problem that I am having is primarily with the swords (I know


> some algae problems, but heavy water changes have been keeping those in 
> check.


> 	* Nitrate/Nitrite/Ammonia -Low to zero (kordon) 

> > The fish load is moderate

Your problem may be a lack of macro nutrients. Sword plants are heavy 
feeders.  I once corrected a growth problem with my swords by adding 
sodium nitrate.  I put in 1/8 teaspoon in 70 gallon tank. (one gram of 
NaNO3 in 50 gallons water is approx 1ppm of nitrogen). The plant started 
growing again and putting out larger leaves.  I also experimented with 
Ammonium nitrate in tank with pH less than 7.0, but discovered that even at 
much lower dosage 
it killed some fish -- I was hoping the plants sucked up the ammonia much 
faster than they apparently do).  Small amounts of sodium nitrate are not 
toxic at all.  And, it should not fuel the algae, provide that phosphates 
are already extremely low.

Apparently, your tap water does not have enough nitrates to keep the 
plants happy from the massive water changes you mention.  By starving the 
algae, you can also starve your plants.