C. Affinis, Echinodorus, Black Worms, PO Diffusion

Subject: Growing C. affinis

Bruce Hansen wrote:

> Crypt. affinis seems to grow well for some people and not for ot
> too have difficulty and get best results with a layer of spaghnu
> under washed  river sand.

Since placing the peat plates under the substrate in the tank 
where I grow C. affinis, I have had no further trouble.  It is 
dark and vigorous and spreading out nicely.  I suspect that it 
does not tolerate hard (even moderately hard) water well, even in 
the presence of supplemental CO2.

In my tanks without peat, the best its done for me is just "hang 
on" without any increase.  It also turns pale and "muddy" colored.

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Subject: Echinodorus sp.
> > Uruaguay Sword (Muratius)--they wanted $20 for these!
> I bought a couple of swords from Mike at Delaware Aquatics, whic
> Echinodorus uruguayensis.  I haven't seen this name anywhere els
> of them have been growing extremely well in my tank for the past
> Many dark green, narrow leaves per plant, leaves spreading fairl
> reaching just to the surface but not above (18" or so)  Fast gro
> pretty. Perhaps E. muriatus is a synonym for E. uruguayensis.  B
> 20 bucks per plant from Mike. more like 5 or 6.

The Oriental Aquarium catalog lists E. uruguayensis.  The photo 
matches your description.  There is also another Sword listed as 
E. muricatus, but this one is very different looking.  It has long 
petioles with broad cordate leaves.  It is also supposedly a 
larger plant than the former.

The Rataj revision of the genus includes E. uruguayensis, although 
I know that this was not the most recent revision.

Subject: re:black worms

> I don't have a lot of experience with black worms but have seen 
> number of places about using them because they carry/spread inte
> parasites.  I remember one warning on this in a shipment of ange
> Angels Plus in Olean,NY (very nice by the way) and I think the o
> book on raising discus.  Too bad because one of the few live foo
> purchase in this area is black worms.  
> I wonder if its possible to put them in an isolation tank for a 
> a medication for parasites (Metrazinol?  spelling is defintely w
> transfer them?

According to Paul Loiselle, the problem is not parasites but 
bacteria.  He says that it is not possible to remove these 
bacteria from the worms because they are "normal" bacteria for the 
worms, but pathogenic to many fish.


Subject: phosphate diffusion

I wrote:

> > Most Crypts do fine in my "normal" substrate, which is #1 grav
> > with laterite in the bottom 1/3-1/2.  I also have one shallow 
> > (my paludarium) set up with peat plates and laterite under th
> > gravel.  This is the _only_ tank I have real success with C.
> > affinis in, perhaps because the peat softens my moderately har
> > water.  There are other Crypts in this tank that do well too.

Stephen Pushak wrote:

> As a point of interest, have you tried them with soil? and are y
> saying peat + laterite is about the same for Crypts? I've sure n
> a difference with soil + vermiculite over plain gravel with onl
> Terrapur cones as the only substrate enhancement (old tank).

As I've explained before, I'm not big into experimentation.  When 
I find a system that works _for me with my particular tap water_ I 
tend not to mess with a good thing.  If a plant does _not_ grow 
well, and it's something that I am particularly interested, I try 
other methods until I find something that works.  

I _know_ that soil substrates benefit many (if not most) aquatic 
plants.  But I also know there are dangers involved... The 
possibility that the substrate will go strongly anaerobic and the 
possibility of introducing toxins from garden soil both concern 

My "compromise" is to set up my tanks with an inorganic substrate 
that I have confidence in, and use soil selectively in isolated 
containers where I can remove it or replace it easily depending on 
the needs of a particular plant.  

Considering my conservative nature, this gives me the safety 
margin I like, and the ability to fine tune the substrate to meet 
a particular plants needs.

There were several reasons that I decided to place peat in my 
paludarium.  First, it is one of my smaller "bodies of water" and 
not too big (at least the water section) to tear down completely 
in the event of a failure.  

Second, the shape of the water space and the waterfall make the 
addition of supplemental CO2 problematic.  With my high pH tap 
water, (pH about 8.2) I was extremely limited as to what submerged 
plants I could use.  This was due to the lack of CO2, but I 
suspect also partially to the high pH itself. While peat would not 
necessarily add much CO2, it _would_ lower the pH and soften the 

Finally, I was particularly interested in getting a stand of C. 
affinis growing that had come from another hobbyist.  In his tank, 
the plant had literally imbedded itself in large peat plates, and 
was obviously growing well. (and had been for about 7 years)

After trying the plant in my other set-ups with less than 
spectacular success, I decided to give the peat plates a try. I 
realized that the dangers of it going anaerobic were greater, but 
the possible benefits of lower pH and hardness, plus the smaller 
chances of toxic substances made me choose the peat plates over 
garden soil.

My experience has been that it _does_ give me more lee way as far 
as the species I can use in the tank is concerned.  The C. affinis 
 has done _much_ better.  Growth of the other Crypts has always 
been a little better in this tank than my other tanks, I suspect 
due to the strong water current. (The exception is C. wendti, with 
grows well in this tank, but reaches truly spectacular proportions 
in my high light, CO2 supplemented 70G tank)

> > I'm not arguing here, but I _am_ questioning.  I have been tol
> > others that phosphate (and presumably other substances as well
> > will diffuse out of the substrate and into the water.  This wo
> > certainly jibe with my experiences the few times that I used D
> > plant tabs in strongly lit tanks... I immediately got high
> > phosphate readings and algae growth in the tanks, which only
> > abated after a couple of months of stepped-up, larger than nor
> > water changes.
> Hmm... I recall a heated discussion about rates of nutrient
> diffusion into substrates before. I'd been suggesting that the
> use of vermiculite would make the substrate more permeable and
> facilitate diffusion. The authoritative opinion was that nutrien
> diffusion in substrates is very, very slow.  I suppose that ther
> are mechanisms for diffusion other than the random kinetic
> jiggling of molecules and that diffusion rates are also
> dependent upon molecular diameters, electro-valent polarities
> and other technical jargon outside my domain of expertise. ;-)
> Your observations suggest something was happening to make
> the phosphate come out. I assume there was no artificial
> circulation?

I remember the arguments too.  I don't know the science behind the 
phenomenon, but _every_ time I've placed phosphate containing 
plant food _deep_ in my substrate, (and no, there is no form of 
substrate circulation in these tanks other than plant roots) I've 
had algae blooms right afterwards.  Doug Valverde just E-mailed me 
and said he has had the same problem.  I don't know how it gets 
into the water, but I have no measurable phosphate before the 
addition, and _very_ measurable phosphate afterwards. (just to 
answer that question ahead of time, I do _not_ vacuum or otherwise 
disturb my substrate.
> My hypothesis is that the flow rates into the substrate and
> into the plant roots will generally exceed phosphate ion diffusi
> against the flow. If anyone knows differently, please contradic
> me. ;-)

This has been contrary to my experience.  Of course, soil is much 
denser than gravel, so I suppose that the soil might "trap" the 
fertilizer more completely than a gravel/laterite substrate would.

Karen Randall
Aquatic Gardeners Assoc.
Boston, MA