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Enough co2?

2K views 21 replies 7 participants last post by  javajive1981 
#1 ·
Hello.

I have a 55g with four fancy goldfish and i was wondering if the fish alone can provide my plants with enough Co2 and ferts on their own? I have amazon swords, anubias, java ferns and lots of crypts.

I am using excel and root tabs for the swords. My lighting is 2wpg i was wondering if growth could be better with DIY Co2 i just have plain gravel.
 
#2 ·
2 WPG does not tell us a lot about your lighting situation; with the advent of newer and more efficient lights, the watt per gallon guideline has fallen out of disuse, as it is only applicable to T12 bulbs.

For example, 2 WPG of T5HO lighting would be very different from 2 WPG of T12 lighting, and hence, we do not really use watts per gallon as a good measure of lighting anymore.

In any case, to answer your original question, fish do not generally provide enough CO2 to meet the demands of plants.
 
#6 ·
I cannot afford a proper Co2 setup as I've spent all my money on the tank, filter and plants. DIY would be the best i could do.
The plants do seem to be growing quite well so maybe i should just be patient and stick with the excel. Although it is very expensive
 
#7 ·
DIY CO2 on a 55 gallon aquarium could work, but would require several 2 litre bottles in order for it to achieve the necessary CO2 levels.

Excel is an option, but as you have realized, can be very expensive for a 55 gallon aquarium. In the long run, using a pressurized CO2 system would be much more economical.
 
#10 ·
The algae is being caused by the fact goldfish are fun to feed and we tend to do it way too often!!!!!!

If you're happy with your plant growth as is, don't bother with CO2, as high CO2 and goldfish don't mix.

To lessen the amount of algae, cut back on feeding, shorten the photoperiod and do more water changes. Adding some excel will also definitely help as well.
 
#11 ·
Most tank plants won't benefit from CO2 because of poor light or more likely poor nutrients in substrate.
I'm sure most here know that plants breath oxygen, they eat CO2.

Also adding CO2 can increase or decrease pH depending on carbonates.

Most importantly, increasing CO2 can kill fish in marginal O2 tanks because of partial pressure issues at the gills. Excel is also a reducing agent so it can also kill fish in marginal O2 tanks.
 
#13 ·
Greg Morin has a brilliant explanation in the downloadable document at
http://www.seachem.com/Library/Articles.html#PlantChemistry

Warning, it can be tough going if you're new to chemistry although he does a creditable job of explaining Le Chatelier's Law.
http://en.wikipedia.org/wiki/Le_Chatelier's_principle

CO2, buffer and water interactions paraphrased...

The carbonic acid concentration decreases so as to bring the system back into equilibrium with the new lower level of CO2. When
the carbonic acid level drops, the bicarbonate level drops as well which in turn yields a higher pH (dropping levels of bicarbonate necessarily produce a drop in hydroniumion). Likewise, an increase in CO
2 will result in an increase in carbonic acid, followed by an increase in bicarbonate and its concomitant hydronium ion, which results in a pH decrease.

This is why medecine and aquarium husbandry are never straight forward.;)

 
#14 ·
@darkblade48
I posted some info regarding CO2 ph effects with buffering.
It is being withheld by the moderator???
I can possibly get it to you on the msg system here if you're keen.
The same chemistry explains why moderate increases co2 can kill fish as most of us animal earthlings use carbonate buffers to transport co2 for disposal.
 
#16 · (Edited)
Links to outside sites are generally reviewed before being allowed, I believe (this is true for new users). I have approved your post.

Thanks for the links; I will be sure to read them in detail. I am a scientist by background, so this is quite interesting to me ;)
 
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