Urgent** adding fish with CO2

[hartgirl]

A couple of people on a local group are trying to scare me out of adding fish to a tank with co2. The drop checker (the plastic Fluval kind) is reading yellow, but it reads yellow on another tank too and the fish are fine. They don't have a problem with the color, but say that I should remove the co2 for at least a day, and then start up with it again. I questioned that, because the co2 is just going to be strong right away again once I put it back in the tank (it's diy so I can't regulate it) ...so would just drip acclimating the new fish so they're used to the co2 levels be good enough? (I am going out to test my kh now to make sure the ph is not actually that high...I ran out of solution). TIA!


Sent from my iPhone using Aquarium Advice

 

[Brookster123]

I've done this with many fish including rams.. shouldn't be an issue so long as they're acclimated properly.

Sent from my SAMSUNG-SM-G900A using Aquarium Advice mobile app

 

[ScotJudd]

This is just my experience and not through research.
When I introduce new fish I turn off the Co2 the day before and turn it on after a couple of days at a slow bubble rate. I increase the rate over many days until I get to where I want, but I don't take the drop tester to yellow, more of a yellowy/green. My plant growth is good and are not affected by this.


Sent from my iPad using Aquarium Advice

 

[ScotJudd]

Sorry, just re-read your post and you can't regulate your Co2. I would still leave off the Co2 until the fish have settled and recovered from the trauma of netting bagging etc..


Sent from my iPad using Aquarium Advice

 

[ImACoolguy]

Also usually the drop checker fluid needs replaced every 2-3 weeks I think to stay accurate.


Caleb

 

[IllusionX]

I have added discus to our 65g community and tank. DIY Co2 here and no ill effect.

 

[PerfectDepth]

Just watch them closely. A yellow drop-checker could mean 45 ppm but could also easily be 100+. I don't like to rely on drop checkers at higher concentrations. You could compare your tank pH to the pH of a cup of degassed tank water to get a better idea of the actual concentration.


Sent from my iPhone using Aquarium Advice

 

[Rpeinhardt]

DIY CO2 is pretty weak unless you've got a number of fermentation containers working for you.

Even so, just acclimate the new additions properly and don't worry.

 

[Mebbid]

Fish largely dont care about the difference in ph when its caused by co2 when it comes to osmotic shock (ph shock)

They can be suffocated, but you will be able to see that before they die to give you a chance to intervene.

 

[PerfectDepth]

^Right. I should clarify that I was only referring to testing pH in order to know the daily drop. A drop of around 1.3 to 1.4 degrees starts to get into dangerous territory, not because of pH shock but because of the high concentration of co2.


Sent from my iPhone using Aquarium Advice

 

[hartgirl]

Thanks everyone! Just for good measure, I took it out. I was also curious what my co2 levels REALLY were, because you're right, yellow could mean 30-110ppm!! So I tested my kh and it's about 100-120 and the ph is about 7....so I'm figuring the co2 to be about 30-45ppm. Is that correct?? I recently had an unfortunate experience on a tank running pressurized co2- whole tank dumped and I lost everything Now I am just a little paranoid, even though I know with diy it can be hard to do any crazy damage. I am running two 2 liter bottles on 30 gallons. I figured since I run a slightly larger mix (two 3 liter bottles) on my 40 gallon that should be ok?


Sent from my iPhone using Aquarium Advice

 

[PerfectDepth]

Thanks everyone! Just for good measure, I took it out. I was also curious what my co2 levels REALLY were, because you're right, yellow could mean 30-110ppm!! So I tested my kh and it's about 100-120 and the ph is about 7....so I'm figuring the co2 to be about 30-45ppm. Is that correct??

Maybe more like 20 ppm, actually. If the drop checker is yellow, though, that doesn't seem correct. To get a better estimate, disregard the tank's kH and just measure how far the pH drops from the baseline pH. Like I mentioned, just set out a cup of tank water overnight, then test the pH and compare to the lowest pH of the tank when the co2 is running. A drop of 1 degree will be roughly 30 ppm.

I recently had an unfortunate experience on a tank running pressurized co2- whole tank dumped and I lost everything Now I am just a little paranoid, even though I know with diy it can be hard to do any crazy damage. I am running two 2 liter bottles on 30 gallons. I figured since I run a slightly larger mix (two 3 liter bottles) on my 40 gallon that should be ok?

It's hard to say. What really matters is not the BPS or the size or amount of bottles, but how much co2 is actually being dissolved and how quickly it is gassing off (as well as the demand). To regulate DIY CO2, I like to take advantage of the fact that the dissolution rate of CO2 will slow down as concentration increases. I use an internal reactor with a powerhead. As the concentration increases, the co2 does not dissolve as quickly so the gas will slowly build up inside the reactor to the point where the "excess" co2 will just escape the reactor and bubble to the surface. At this point, the co2 concentration reaches an equilibrium and stays the same for the remainder of the photoperiod. You can also put the powerhead on a timer so it only runs during the day.

 

[hartgirl]

Maybe more like 20 ppm, actually. If the drop checker is yellow, though, that doesn't seem correct. To get a better estimate, disregard the tank's kH and just measure how far the pH drops from the baseline pH. Like I mentioned, just set out a cup of tank water overnight, then test the pH and compare to the lowest pH of the tank when the co2 is running. A drop of 1 degree will be roughly 30 ppm.




It's hard to say. What really matters is not the BPS or the size or amount of bottles, but how much co2 is actually being dissolved and how quickly it is gassing off (as well as the demand). To regulate DIY CO2, I like to take advantage of the fact that the dissolution rate of CO2 will slow down as concentration increases. I use an internal reactor with a powerhead. As the concentration increases, the co2 does not dissolve as quickly so the gas will slowly build up inside the reactor to the point where the "excess" co2 will just escape the reactor and bubble to the surface. At this point, the co2 concentration reaches an equilibrium and stays the same for the remainder of the photoperiod. You can also put the powerhead on a timer so it only runs during the day.

I know my baseline pH is 7.4....always 7.4 and never deviates from that. So with co2 it goes down to about 7. I'm hoping 20ppm is more accurate - it could even be just above that and the drop checker could register yellow. It's the fluval brand and I had just replaced the solution inside....


Sent from my iPhone using Aquarium Advice

 

[PerfectDepth]

I don't know.. With only a 0.4 drop it should actually be less than 10 ppm and the drop checker should be blue to blue-green. How long did you let the cup of water sit out before testing baseline pH? I would maybe try the high-range ph kit too for a "second opinion."


Sent from my iPhone using Aquarium Advice

 

[hartgirl]

My high range is what I measured with. It's what the ph was before I added the co2. The regular ph test kit shows dark blue (7.6) but the high range shows suuuuper light brown (7.4)....the difference in color between 7 and 6.8 is minuscule so it could have been 6.8 if you look at the color in different light ....


Sent from my iPhone using Aquarium Advice