Unbelieveable CO2 Saturation

[WarEagleNR88]

The post title says it all. This is why... almost 130 ppm dissolved CO2.

It's been kind of an experiment in my 10G--no fish, only snails--and that's to test different variables. I usually test on Wednesday or Sunday or both. This past week though, I cranked the bubble counter to about 3-4 bubbles per second just to see how high I could get the CO2. It's so fast, I can barely count them.

I'm using a milwaukee regulator w/ solenoid and bubble counter, milwaukee pH controller, and a 5# CO2 bottle. I've been injecting the CO2 directly into the filter intake of my Penguin 125 under 40W of 6500K PC Lights with bad reflectors. And these are the Walmart PC Lights of America bulbs, too. Before I bought the controller I was using a simple Red Sea test kit for low pH now I use the milwaukee controller, a Hagen GH/KH test for the KH, and the nitrates using a Red Sea nitrate test kit. This has been going on for about 3 months. The nitrates have been around 0-5 ppm constantly. More times than not it's been nearly zero. The pH has been around 7.0 until as of late. The KH has been around 10 to 11 (hard to tell with my test kit). Tonight I tested, here are the results.

pH: ~6.4
KH: 190 ppm or 10.6* (19 drops of solution)
Temp: ~78*F
Nitrate: ~0 ppm (maybe 1)

Using Chuck Gadd's trusty Planted Aquarium Calculator, I calculate that to be 127 ppm of dissolved CO2. Lots of O2 saturation!

Why I'm not having explosive growth is this--very little available nutrients. Every time I dose just a little, my plants seem to grow inches overnight. And then they stop growing as they've used up the available macros. Then hair algae grows. Then I've got to cut the plants and replant because it is a 10G.

Part II of the experiment: dose an insane amount of Potassium Nitrate. Next week I'll follow up. It will be interesting to see what will happen. I'm expecting other nutrients will not be available to give the plants what they need and the plants will show a lot of stress by next Wednesday. I'm not sure what the algae will do though. But the plants will survive, they always do.

 

[czcz]

Very cool. FWIW, I have the same thing going and have found EI's the best standard to run experiments against. For example, better to control macro and nutrient input, then choose one thing as the variable, so you know your results are because of the variable instead of a nutrient bottoming out. Only a suggestion after doing something similar as your next experiment in my control tank, then having to delay experiments for some time as I battled algae. (I still battle slight GW months after inducing it in that tank.) As you know, a 10 is real easy to reset through water changes multiple times a week.

What plants are you using for indicators?

Very interested in your results.

 

[WarEagleNR88]

As you know, a 10 is real easy to reset through water changes multiple times a week.

What plants are you using for indicators?

Yes, a 10G is very easy to use for crazy experiments, even when you weren't planning to do so!

As far as plants go, I'm not sure on the exact names, but I'll try to see if I can name them all. Travis you may need to help me out if you remember the exotics you sent me. Here goes--I took some of the names from Plantgeek,Takashi Amano's Vol 2 NA world, and Tropica as I found them, they may not be right. I tried to get as close as I could.

Anubias barteri var. angustifolia
Anubias barteri var. nana "Petite"
Echinodorus tenellus
Echinodorus amazonicus (two small ones that I forced to stay small)
Echinodorus x barthii
Hydrocotyle verticillata
Hydrocotyle sp.
Ludwigia repens "Rubin"
Lobelia cardinalis "Small Form"
Marsilea sp.

 

[travis simonson]

Disclaimer: I know WarEagle (aka Ben) from a long time ago. He is a test pilot (and I'm not joking about that) and has a tendency to want to push things as far as they will go (hope I haven't pissed you off yet Ben ). Ben flies A-10s for the USAF and comes home to play with his tanks, so give him a break if he wants to push things a bit

I like the high CO2 experiments man. Please keep us informed as to your results. I know I'm pretty darned curious to see how things work

 

[WarEagleNR88]

Disclaimer: I know WarEagle (aka Ben) from a long time ago. He is a test pilot (and I'm not joking about that) and has a tendency to want to push things as far as they will go (hope I haven't *beep* you off yet Ben ). Ben flies A-10s for the USAF and comes home to play with his tanks, so give him a break if he wants to push things a bit

I like the high CO2 experiments man. Please keep us informed as to your results. I know I'm pretty darned curious to see how things work

Yep we've definitely known each other for a while. Kinda weird how this little hobby can give you friends all over the country or even the world, eh?

And man, you know you can't *beep* me off. It takes a lot for me to get angry.

I'm not flying an A-10 yet, Travis. It's a T-38C. I'm still working on the getting the wings part of it, but I do want to fly the A-10. Why do you think it's taking me so long to get that 20G project together? I'm flying twice today and only once solo unlike what I told you last night. Solo in formation and with an IP next for some Advanced Handling Characteristics maneuvers. Should be a good time!

Does the species list look correct as far as you can remember? I still have those two species of Hydrocotyle, I'm just not really sure what the smaller diameter and shorter plant is. And those little chaining swords, they were E. tenellus right?

Alright, thanks for the post Travis. I was observing the tank last night and it's looking very healthy. Algae is growing and multiplying along with the snails, but it's not bad. And it's only hair algae, how hard can it be to get rid of?

 

[WarEagleNR88]

Part II

Ok, so I waited a week and wow has the growth been fantastic. I think micros are starting to limit growth--and maybe space too. It's hard to tell. CO2 is definitely not lacking. And just fyi, I am keeping the CO2 going about 4 bubbles per second 24/7. Last Wednesday, I mixed up a 20 ounce bottle of RO/DI water with 1 tablespoon of Potassium Nitrate. With 1 tablespoon in 20 ounces (600 mL) of water , it should have raised the Nitrates well into the high 200s on a 10G. Stats (Sorry I didn't test tonight, will test tomorrow night):

pH: ~5.9
KH: ?
Temp: ~78*F
Nitrate: ?

If my KH is still the same, and here goes the crazy part, I have 400 ppm of dissolved CO2. The KH should be the same. I don't really see any snails anymore, I don't think they made it as I see shells, but no snails (say that three times fast). I'm starting to not even believe these numbers.

Here are pictures of the "transformation." Notice the growth of the swords and the Ludwigia repens "Rubin". Right now, ever node on the L. repens has a water root AND a new stem "sprout." I think this week I'll retrim and dose a tiny amount of Plantex CSM+B. Hypothesis is an explosion in growth and algae growth should decline. I think if I get all of the nutrients in line in proper amounts, plants will grow out of my tank, into the canopy, and on to the floor.

2 April - pH 7.0, KH 190 ppm, NO3 <1 ppm, CO2 32 ppm

8 April - pH 6.5, KH 190 ppm, NO3 <1 ppm, CO2 101 ppm

12 April - pH 6.4, KH 190 ppm, NO3 <1 ppm, CO2 130 ppm

19 April - pH 5.9, KH ?, NO3 ?, CO2 ~400 ppm

I wonder at what point KH and pH are no longer linear? 400 ppm is just flat out ridiculous. Please feel free to comment. And I'll update my next part of the experiment.

 

[Glenc]

That is absolutly insane!! Look at the growth! I'm still shaking my head. Those plants will be out of the tank shortly.

 

[7Enigma]

Yeah I would bet the snails wouldn't make it. Even a well established tank that slowly rises to that level (say no live plants and never PWC's, only adding water that evaporates, would probably not support snails. You will get some additional ammonia from them that might REALLY start an algae outbreak in the tank.

As for the plant growth, it is amazing. The large leaf plant middle-right in your tank appears to have almost doubled in size in those 7 days. Incredible growth especially if you take into consideration that you are most definately starving the plants of other macros (probably phosphates, and most likely iron).

 

[czcz]

Sweet. Its interesting the plants are growing despite limiting factors with macros. Also interesting that algae is surviving high CO2 since its said lower-order plants can't survive such concentrations.

When you're done observing extremes, are you planning on scaling it back and messing with parameters you'd feel comfortable introducing fauna to? Only curious.

 

[WarEagleNR88]

AHHHH.... bad news.... and the tank didn't blow up from having a pH of 3.0.

I ran out of CO2 today so I didn't get to continue with my experiment. . I've gotta get another 5# bottle of CO2 tomorrow from Airgas. That bottle lasted about 2 months! The pH was 7.1 when I got home today at 8 pm. It is now 8.1 at midnight... that's a full point in 4 hours?!? I wonder if the plants were so accustomed to receiving large quantities of CO2 that they absorbed all of the dissolved CO2, converting it into oxygen which drove the pH even higher than my ambient 7.5? I wish I were keeping track of dissolved O2.

I have no idea what these very large pH shifts will do to the plants. I was wondering how low will the pH go and now how high will it go? It's not like it's going to blow up if it gets to 5.0 or 9.0, but will the plants start to melt? Or will they perform at their peak when it's low and algae thrive when it's high?

I think I'll check my controller with the test solutions tomorrow and make sure it is still reading correctly. I'll also try to do a full water test to check everything I can using all of the tests I have. Ammonia, Nitrite, Nitrate, pH (with controller and with drops) Alkalinity, and Hardness (GH and KH). Of course I'll do this before I plug the CO2 back up.

And yes, I will be scaling it all back once I've had my heart's content. That's fairly easy to do on a fishless 10G where any cycle that happens is utilized by the plants. I just thought I'd check out what happens when plants are pushed to their limits. And I bet any ammonia that is produced will immediately be put to work by the plants--once the CO2 is back up tomorrow. Algae Smalgae I ain't scared.

What an experiment! Right now, there seems to be too many uncontrolled variables at the moment to really draw any conclusions. Hopefully I can bottle some of these observations together to make something coherent and beneficial!

 

[czcz]

Right now, there seems to be too many uncontrolled variables at the moment to really draw any conclusions.

At the very least, 5lbs of CO2 in 2months for a 10gal sets a new standard for "hardcore"

BTW, thank you for continuing updates and experiments!

 

[dskidmore]

Very cool. I feel inspired. I don't have the $$ for solenoids right now, but I could keep a better eye on my DIY CO2 generators.

 

[travis simonson]

Ben I'm going to report you to PETA (Plants for the Ethical Treatment of Ammonia ).

I have never heard of anyone doing what you're doing. Although (knowing a little bit about Ben's background) I am not very surprised. I love extreme experiments like this. I am waiting eagerly to see how things go with the next five pounds