Suggestion about restocking to fight algae?

> From: Alan Holloway <llabh at utxdp_dp.utexas.edu>
> I'm fit to be tied: I started ye olde plant tank two months
> ago, and it's looking ugly.  

It takes a while for a tank to stabilize. We typically get many
different types of algae as a new tank goes through its startup phase
over a period of 4-6 months. 

> Parameters: 40 gallons, Tex-Blast gravel with Dupla K; water straight
> out of reverse osmosis; 

Plants get a lot of nutrients from the water. RO water has most of
them removed and you need to use the right additives to make it
"right" for plants. 

> pH 7.5; GH 8; KH 4; 

You've added something to get some GH and KH.  What?

> temp 81; lighting, 2 Tritons and one Coralife 50/50 left on 10 hours
> daily; 

Should be OK.

> fish load, 3 mollies and a pair of Aequidens dorsiger.  I have
> green algae, hair algae and the ever-dreaded brush algae. Baensch
> refers to green algae as "fur algae," which in my experience is the
> most commonly encountered type--it's the stuff that covers a wide area
> in a stealty, innocuous manner.  

You need more than the mollies for algae control. Conditions suitable
for plants are also suitable for algae. We have had really good
success with farlowellas, otocinclus and "real" Siamese Algae Eaters.
Different fish eat different algae; there is not "general purpose"
algae eater.  The SAE will control the red brush algae and farlies or
otos will help on the softer stuff. 

> Oh yeah, and I've used yeast culture CO2, but using KH vs pH extra-
> polations, I saw little reason to continue to bother.  I was using two
> one-liter bottles.

What CO2 levels did you see? 10-20 ppm is a good range to shoot for. 
Your pH/KH readings suggest <5ppm. 

> The plants cost way too much (well over $100 from TFP) yet aren't
> enough to outcompete with algae for nutrients.

An excellent article by Diana Walsted in the most recent TAG suggested
a more reasonable (to me) scenario why densely planted tanks don't
seem to have much algae.  Plants give of "allelochemicals" (I think I
spelled that right) which inhibit algae growth and, in some cases,
inhibit other plant growth.  I would suspect that faster growing
plants give of more allelochemicals than slower growing plants and
certain plants give off more than others (Cambomba caroliniana was
shown to produce more than most aquatic plants).  Perhaps a planting
of faster growing plants would help at first. 

> Which brings up another factor.  I use Dupla's 24 fertilizer, or at
> least I used to, but now I'm mighty leery about feeding hungry algae.

You need to use *both* Duplaplant tablets *and* Duplaplant 24 drops 
to achieve a balanced "diet" for the plants. A lot of folks don't seem
to realize this. Tablets are used when you change water every two
weeks and drops are used daily. 

> So, I've decided to semi-tear down the tank, stripping the
> Amazons' leaves and plucking whatever else looks like 
> doesn't belong in the aquarium.  I've ordered 50 corkscrew
> vallisneria from Aquarium Driftwood of Semmes, Alabama, to 
> make sure the algae get a bit more competition for resources.
> What else should I do?  What irreconcileable mistakes have I
> made that others can avoid making?

Get a larger variety of fast growing stem plants: Hygrophila sp.,
Bacopa sp. and Rotala sp. are recommended.  Forget the Crypts and
Anubias until the tank is established. 

Make sure your water is not "too pure" and use the proper fertilizers. 

Get a bigger variety of algae eaters. 

Make sure your CO2 setup is working. 

Your lighting is good.