[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: Algae:plant competition and Carbon

Dear Tom,

>It would again seem that extra Carbon is the main missing nutrient for the
>plants. More than this 106 ratio but close to 5 time that. Plants perhaps 
>even a higher C ratio than the kelps. If this is supplied in great enough
>quantity the smaller algae will not have the same advantages but the larger 
>will. It makes sense since the majority of the C is used for support while 
>algae can get by with far less Carbon.

>Still doubtful of the importance of carbon?

No, Tom, I'm convinced!  Set up my 88 gal tank over Easter, have been adding 
Flourish Excel (carbon) daily, and also Potassium, as that has always been a 
limiting factor in my tanks - the combination of those plus some more light 
(the All Glass compact fluro strip with two 55 watt, high temp bulbs that were 
part of the kit, so not a high light level by any means!), have caused amazing 
growth in just a couple of weeks.

Further support comes from the Planted Aquaria magazine article in the new 
Spring 2001 issue, "CO2, Light, and Growth of Aquatic Plants", by Ole 
Pedersen, Claus Christensen and Troels Andersen - for those who haven't seen 
it, I'll paraphrase briefly: if you start off with a low light, low CO2 tank, 
you get low growth (1.1%); if you add CO2 only, you get 4.1% growth with a 
high CO2 level.  If you add light only, you get an increase of 6.5% growth at 
the highest level.

If you add both CO2 and light to moderate levels, you get 9.2% growth; if you 
add both at high levels, you get 14.8% growth.

So I'm very happy with my 9.2% (or whatever!) increase - the hygro stems have 
turned into a thicket already, the cabomba is looking healthy for a change, my 
echinodorus Rubin has doubled in size, the aponogeton basket leaf has come 
back from the dead (from two small leaves to about 6, with the original two 
now nice and big), etc etc.

I've also added the two supplements to my low light tanks, and seen some 
growth, about half that of the big tank which has extra light as well, which 
is also consistent with the experiment above.

So yes, Tom, I'm convinced about the need for carbon!  And a bit more light!

Kind regards,

Susi Barber