[APD] RE: bleach dip for Anubias

["Steve Pushak" <teban at powersonic_bc.ca>]

Clint Brearley asked about curing BBA on Anubias:

> If I dip them in a 1:20
> bleach solution for 4 minutes or so, will this clean the
> leaves up okay, or will I still need to prune?

Bleach treatment (1 part bleach diluted in 19 parts water) will
eradicate BBA in about 3 minutes but you can treat Anubias to 5 minutes
or longer without fear of any damage to the plant. BBA will disappear
from an aquarium by the leaf removal method for other plants & bleaching
Anubias & cleaning all objects & glass with visible algae and by
increasing CO2 dosing. This cleans up the leaves but is not necessarily
a permanent cure since the BBA can reattach later. There will always be
a few colonies lurking in the aquarium.

There's no need to remove healthy leaves of Anubias; I do remove damaged
or yellow leaves. I've heard that temporary removal & bleaching is a
good approach for cleaning Anubias leaves of spot algae too. How many
kinds of spot algae are there? Do we classify it as epiphytic
non-filamentous?

> should I just
> leave it alone and
> let the snails/SAEs clean it up over time?

Snails don't eat BBA. SAEs do but don't touch spot algae.

You also need to increase the amount of CO2 in your system. Black brush
algae is a kind of marine algae & thrives in alkaline conditions. Drop
the pH and it seems not to regrow especially if you maintain good growth
conditions for the plants.

BBA will not completely disappear but can remain incipient in a tank for
a long time until conditions become favourable for its reappearance. Its
wise to give all plants a prophylactic dip in diluted bleach & to
quarantine fish before introduction to a planted tank. The quarantine
tank should be unlighted. You can read more about Paul Krombholz's
bleach protocol on the Krib & probably in the APD archives; not sure how
far back the archives go.

There are two long term strategies:
a) sterilize the tank & additions from the start
b) remove BBA manually & maintain conditions favourable to plant growth
but not favourable to BBA

The problem with a) is that its easy to re-contaminate a tank. I always
start my tanks that way and keep them as clean as possible. Often I get
contamination from Spirogyra but you can knock it back with a lengthy
black out & frequent water & nutrient exchange.

I find BBA relatively easy to deal with using the above two procedures
together. In my experience filamentous thread algae of various types are
more problematic. I suspect that competition for light may be one
strategy that permits macrophytes to out-grow or dominate some types of
filament algae. I think competing for light would work for filament
algae which does not have a motile stage.

Thomas  has talked about maintaining conditions where motile forms of
epiphytic algae can't or don't get attached to new, clean leaves. I'd
enjoy reading more from him on this hypothesis.

If I understand what Thomas & Roger say, nutrient competition is not the
mechanism that permits macrophytes to out-compete filament algae. I
submit that it has to be competition of some form. Over shading is one
mechanism of species succession. Its difficult to talk in generalities
because its probably different depending upon the species of macrophyte
and algae in competition.

Perhaps there is a way that healthy plant leaves have of preventing
attachment of motile epiphytic algae. I'd love to hear a new hypothesis
to explain the mechanism. Speculation might lead to a very interesting
research proposal! How could you investigate it?

I hope this leads into an interesting discussion thread.

Steve


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