Flourish Excel vs Pressurized CO2?

[Barmy]

Hey everyone.

I'm thinking about setting up a small planted tank in the near future. The tank I'll be using is 2 feet x 12 inch x 15 inch and holds about 18 gallons. I intend to use nutrient-rich soils, and to dose all the required Seachem ferts. The tank will have around 3 watts of light per gallon, and one of my goals with this tank will be to grow a nice carpet plant (perhaps glosso? Or one of the smaller grasses).

The only element of the tank then left for me to decide is how I will introduce CO2 into the system. New CO2 kits cost quite a large amount, and so I've been looking at Flourish Excel as an alternative. I've worked out that it would take at least a couple of years for the cost of buying Excel to overtake the initial startup cost of a pressurized kit. However, I am unsure how Excel compares to CO2 in its gaseous state in terms of efficiency and expected growth rate of plants, and I'm hoping someone here with a more intimate knowledge of the product could help me out. I want to know, given the small size of my tank and the goals listed above, would Flourish Excel provide me with results comparable to pressurized CO2 injection? And if not, what would the differences actually be (ie. in terms of grwoth rate, which plants would thrive and which wouldn't, etc).

I realize that different plants have different requirements and so the answer to this question might not be so straight forward, but a general indication of what to expect is all I'm after.

Cheers

[Tech Support AN]

Congratulations on your new tank! I personally have a heavily planted tank here at Seachem and use Flourish Excel on a daily basis. I have had fantastic results from it, as with the other planted tanks around the office.

Here is a quote from an article on our website about Carbon in the Aquarium: "If one is not quite ready for the initial investment in a CO2 injection system but would still like to enjoy some of the benefits of adding additional carbon there is an alternative: Flourish Excel. Flourish Excel provides a simple organic carbon molecule (similar to what is described above in the photosynthesis discussion) that plants can use as a building block for more complex carbohydrates. Because Flourish Excel is an organic carbon source it does not impact pH." If you would like to read this article in full, as I believe that it will prove very helpful to you, please follow this link: http://www.seachem.com/Library/Articles/Carbon_in_the_Planted_Aquarium.pdf.

Flourish Excel provides the same benefit as CO2, i.e. it provides the plants with a source of carbon for growth just as CO2 provides them with carbon. However CO2 by itself will give you quantitatively more growth than Excel by itself, although Excel does provide a substantial amount in comparison. If CO2 is a 10, Excel is a 6-7.

I also maintain a 265 gallon planted tank that has had a flourishing bottom layer of glossostigma, without the use of CO2, using only Flourish Excel and other ferts from the Flourish line. They enjoy very high lighting and once established, they grow very fast. So I think that you can be very successful with glosso in your setup by using Excel as you carbon source. I hope that this information has helped and if you have any additional questions, please don't hesitate to ask us!

[Fanie Jordaan]

The one downside of using pressurised CO2 in a heavily fish stocked planted setup is the need to aerate at night as both fish and plants then consume O2. Also - depending on the type of plants and groth rate, O2 is not necessarily generated by the plants in sufficient amounts to sustain O2 hungry large fish.

Does Flourish Excel have the same tendency to evaporate through agitation of the water surface as is the case with gaseous CO2?

[Tech Support AN]

Thanks for the post. I believe your question has been addressed in the FAQ page on Flourish Excel:

Q: Will an airstone or surface agitation decrease the effectiveness of Excel as it would decrease the effectiveness of CO2 injection?? What effect would an airstone/agitation have on Excel's effective CO2 levels?

A: An air stone or other surface agitation will not impact the effectiveness of Flourish Excel. Flourish Excel is not CO2, it is simply a readily available source of carbon. This is an intermediate source and more readily available than CO2 and will not interfere with the uptake of CO2 as a carbon source.

[Fanie Jordaan]

Thank you - your reply is appreciated.

[Tech Support EH]

You're very welcome!