Dangers Of Adding Co2

[Byron]

I came across this article this morning and though I would share it.  What particularly caught me was not the actual issue of the possible detrimental effects of adding diffused CO2, but Nathan Hill's comment [my emphasis]: 
 
The problem is, we may have become so focused on the plants that some of us are becoming blinkered to the needs of the fish that live alongside them. In fact, as an aside, I notice a troubling trend in modern aquarium keepers, where the measure of welfare seems to be steeped solely in terms of survival: if the fishes live, things are good, if the fishes die, things are bad. This is a broad observation, however, and not one specifically targeted at aquascapers. Across the board, it is an inappropriate position to take.
 
This is a trend I have noted in a number of threads.  For now, I'll say no more, other than to echo Nathan's concluding thoughts:
 
It might only be a small, cheap fish, but it still deserves a decent quality of life, right? And if we can find a way of improving on that quality of life, then I say we at least try.
 
Byron.
 
http/www.practicalfishkeeping.co.uk/content.php?sid=6769&utm_source=PFK_newsletter&utm_medium=email&utm_campaign=June_5_2015&utm_term=Does_CO2_injection_cause_disease?&utm_content=html

 

[Ch4rlie]

A good observation I have to say, and one that I have thought of before.
 
There does seem to be a trend of aquascapers more concerned about their plants and not really researching if co2, liquid carbon, fertilisers will have any impact on their stocking.
 
For example, some fertiliser may contain high amounts of iron and copper, this may have a detrimental effect on inverts.
 
A happy balance would be for folk to realise their limits on what kind of tank and species of stocking they would like and then study on suitbale plants for these particular species.
 
I won't go on much more, but there is a lot more to this than meets the eye.
 
i my humble opinion, a FISHkepper is just that, someone who enjoys making a habitat that will suit their stocking of choice.

 

[TwoTankAmin]

Al I can offer is my own anecdotal evidence. I ran co2 gas into one tank for close to a dozen years. It was one of 15 - 20 tanks I had running at the time. It was probably the tank I had with the fewest health issues for the fish. I cannot recall ever having medicated it the whole time I had it running. Moreover I got repeated spawns from the farlowellas when they were added to the tank.
 
I never ran a drop checker nor did I do any serious testing of co2 levels. I basically let the plants tell me when it was about right. I never shot for the 30 ppm level ever. I ran a lean level of co2, it was a benefit to the plants and appeared to do no harm to the fish. I shut down that tank about 18 months back and moved the fish to other tanks. I still have many of them doing fine.
 
One can put forth the idea that too much oxygen in a tank can harm fish as well. Just look into super-saturation. We are told dechlors can be overdosed without harming fish. This doesn't mean dumping the whole bottle of dechlor into a tank is safe. Many folks.myself included, have used Excel as a carbon source in tanks. I have been doing this in multiple tanks for many years. I dose according to the directions only because I know overdosing can have harmful effects.
 
Mt point is that article would suggest we not use pressurized co2 in tanks rather than using it at different levels. While I agree with the main point of this thread, that fish health is more than survival vs death, I do not agree with what it implies about the less "fanatical" use of co2 in planted aquaria.
 
 

 
In intensive aquaculture systems, constant monitoring of dissolved CO2 and pH is highly recommended (EFSA, 2008). The upper CO2 limit for salmonids in aquaculture systems ranges from 10 to 20 mg L− 1 (Boyd, 1979 and MacIntyre et al., 2008). According to Blancheton (2000), the CO2 concentration in aquaculture tanks with juvenile and adult sea bream, Sparus aurata, should not exceed 40 mg L− 1. However, some fish species are tolerant of much higher CO2 levels ( Crocker and Cech, 1998, McKenzie et al., 2002 and McKenzie et al., 2003). According to Good et al. (2010) the determination of species-specific CO2 limits for aquaculture is complicated by various factors influencing the toxicity of this gas. These factors include some metals that could change their chemical speciation, becoming more available to exert toxic effects at high water CO2 levels ( Fivelstad et al., 2003a).

from http/www.sciencedirect.com/science/article/pii/S1532045612000841
 
As with anything fishy, there are very few universals. Some fish can handle more co2 in the water than others. Some fish are adapted to living in waters with elevated co2 levels and lower O levels.
 
The one thing I agree on wholeheartedly here is that those folks who push the planted tank thing to its limits and work to maximize their growth and appearance by adding maximum co2 are not usually very concerned about what effect, if any, all of it may have on the fish. The needs of the plants often outweigh the needs of the fish in such tanks.

 

[daizeUK]

I totally agree with TTA. Anecdotally this is something you will hear repeated by folks all over the planted forums, that healthy plants = healthy fish. The health benefits conferred by healthy plants more than compensate for the effects of adding extra nutrients, CO2, liquid carbon etc. unless they are added to excessive extremes.