Re: Aquatic Plants Digest V5 #457

[Thomas Barr <tcbiii at earthlink_net>]

> Any other suggestions on how to get rid of the cyno?  I would like to
> avoid using antibiotics (and I'd need a lot for a tank this size).

You already did one method that worked, not sure what you did after.
Adding antibiotics will not cure the after effects although folks will claim
it does.
It takes about 10-20 days to get BGA back into an area that has been
severely burned, volcanic eruptions etc. It's highly unlikely you'll keep
your tank sterile and BGA free for long.
 
> Should I be brave and add enough of the KNO3 until I read between 5 and
> 10 on my test kit?  This might take a lot of KNO3.

For a 240 gallon tank, 50% weekly water change followed by 1.5teaspoons, 3x
a week, 2 teaspoons ONCE a week, PO4 1/8th teaspoon 2-3x a week, traces 3x a
week 50mls.

> A couple of weeks ago I was adding up to 4 or 5 tablespoons of KNO3 a
> week, in an attempt to get rid of the cyno.  The plants liked it, but
> the cyno still spread.  Is it normal to have to add this much?

Do not do this. You had added 40-50ppm of NO3 at least to this tank on top
of whatever you had in there already. Pleawe, don't trust these kits, I can
tell you can do this much easier and perhaps more accurately by following
the above routine. I use a nice test kit and have trouble telling folks to
buy cheap ones with NO3 and a few other nutrients.
The above routine will work unless you have a massive fish load(no cure
except fish load reduction), Horrid tap water(call and ask to see what the
N-NO3 and PO4 levels are delivered to you) in which case some alterations
can be made(eg you might not need any NO3 or PO4 etc) but many places are
low on these, BUT not always.
  
> (tank info: 240g with a huge wet-dry filter.  light fish load (maybe 8
> guppies, 12 nickle sized angel fish, 6 ottos, 8 SAE, a couple of corys,
> 4 small plecos.) 

Well it's not the fish load, this is pretty light.

> Over half the tank I have 4 T-12 40w tubes; the other
> half has a 96w AH supply compact fluoro tube (the cyno is only on the side
> of the tank with the 96w power compact light).  Plants (lots of val,
> hygophila, ludwigia, swords, etc.) seem to grow fine, if slowly.)

Not much light. This is 256 w/on 240 gal= about a 1 w/gal.
Let's alter the above routine for this lower light level.
Do this weekly instead here:
cut the KNO3 to weekly(1.5Teaspoons), K2SO4 weekly(1.5tsp), PO4, (1/8teasp),
Traces 50mls once a week.
Keep the CO2 up.
Repeat.
Shrimps would be good for this tank. More Cories etc. Need more fish.
    
> As you can tell, I don't know a lot about this stuff, and any help would
> be appreciated.  Thanks,
> 
> Ric

Follow the above and don't trust the kits without double checking with "
Does this seem reasonable?".
If you double the light level, you will need to double the KNO3, PO4, and
traces by adding 2x a week.

Very important:

When the light level increases, you increase the frequency that you dose,
but NOT the individual dosings. Do not add 2x as much once a week etc.

Clean your filter, BGA etc, then try the above dosing routine.
Things should be fine if you don't destabilize things by adding lots of
fert's in there.

Regards, 
Tom Barr