R. macrandra, Alternanthera, Oto's and CF's

 Subject: Rotala macrandra and fertilizers

> By the way, anyone have the secret to keeping rotala macrandra
> healthy, happy, and most of all, red?  I have 6 watts per gal of
> so I think that is not the secret, but I am open to suggestions.
> I have fought to keep this happy since Karen used to be on Fishn
> Thanks all, and look forward to all responses.

Mike, we may have discussed this on Fishnet, but this is what 
works for me.  I assume if you're using 6W/gallon that you also 
have adequate CO2 levels? (minimum of 15 mg/l)  I can't comment on 
your trace element supplements, because I've never used them.  Two 
that I _know_ work are Dupla (drops and tablets) and Horizon 
Mastergrow (my favorite because it works very well, has all 
ingredients listed, and only needs to be added with water changes)

I believe that R. macrandra is a much stronger root feeder than 
you would suspect looking at its structure.  When I tried growing 
it in my gravel/laterite substrate with good light (though not as 
bright as yours) CO2 and trace elements it would get more and more 
spindly.  The stems would eventually get brittle and begin to 
break off low in the tank.  The color was pale and the leaves were 

Then I decided to try the "trick" I've used with Echinodorus for 
years... potting it with soil and laterite.  That was exactly what 
it needed!  It took off like a shot, and now grows as vigorously 
as any Hygro.  The leaves are large and brilliant magenta, and the 
stems are supple, requiring a strong pinch to trim back.  I have 
to keep up with it, or it will completely take over the surface of 
the tank.(which, BTW, is where it does its best branching)

It _still_ needs heavy trace element supplementation and I find it 
necessary to supplement magnesium as well.  When it shows signs of 
slowing down, (about every 4 months or so) I pull the pot.  When I 
un pot it, I find that it is completely root bound, and I suspect 
has exhausted the nutrients available in its limited amount of 
soil.  At that point, since it roots easily and grows fastest on 
new cutting anyway, I toss the roots and the lower (now woody) 
stems and replant fresh growth in the pot.

Grown this way, I have more than I need for my own tanks, and 
plenty to share with others.  I think that many people assume that 
stem plants are not going to be very dependent on the substrate.  
In my experience, this is not the case.  The person I know who 
grows more of this plant than anyone else has a soil substrate in 
the entire tank... I'm just still not that daring ;-)

Subject: Alternanthera

> I think I'm having enough light for Alternanthera. I've been hav
> growing very well for many months. I have 80W over 50g tank.

80W over a 50G tank is still not very much.  Many light hungry 
plants will do just as yours have under inadeqaute light 
conditions... grow quickly for a while, trying to get closer to 
the light, then eventually give up the ghost.  This is still my 

> Maybe the
> substrate is running out of nutrients as it is a little over a y
> I can't seems to find those much-talk-about Dupla or Tropica's 
> fertilizer over here. Have to make do with Tetra's products.

Try potting it with some soil.  You may find that it helps a lot. 
Remember that most Alternanthera species in nature grow as 
marginal plants, not fully submerged.  They need a lot of help in 
the aquarium.

Subject: Brown Otocinclus

> The fish I have now is NOT a flexis. It is EXTREMELY jumpy and I
> have had a hard time getting a good look at it in my tank. I don
> that this fish would be able to harm anything from the way it se
> act. Anyway, what are some species of oto that fit the short des
> gave. Again, I know it is not a O. affinis or O. Flexis.
> I have not seen it "at work" and I will keep everyone posted on
> its algae eating abilities and any negative points. I will try t
> identify it as soon as possible.

There is probably a different Oto-like critter for every little 
rivulet in the Amazon.  I think I remember that there are about 10 
described species of Otocinlus at this time, as well as several 
almost-Otos.  Add to that the fact that undescribed catfish are 
brought in on a regular basis as "contaminants" and it is possible 
that you will never know exactly what you've got.  If they are 
behaving, enjoy them.

Subject: "New" Compact Fluorescents

> Let me tell you how I made a CF setup for a 20gal for much 
> than $110.  I took an old sh**ty incandescent hood and screwed i
> two CF adapters that I got a Home Depot for about 10 bucks each.
> threw away the 3500K bulbs that came with these Phillips adapter
> Then I went and bought the 5000K bulbs (or 7000K if you want) fr
> mail order place for about 6 bucks each. 32 Dollars spent and I 
> 18W of CF on the 20 gallon. And, considering that they put out t
> intensity of a MH, that is plenty of light for a reasonable plan
> tank. And, conveniently enough, this old sh**ty light strip stil
> fits onto my tank cover instead of having these 
> difficult-to-work-with and difficult-to-mount "mini-fixtures."

18W of compact fluorescent on a 20G tank are not really adequate 
for much but low light tolerant plants.  18W of MH wouldn't be 
either if there was such a thing.  (lumens/watt for MH's and the 
better fluorescents, including CF's are fairly comparable)

Karen Randall
Aquatic Gardeners Assoc.
Boston, MA