DIY CO2 and PH

[wildroseofky]

I am getting ready to add diy CO2 to my 29 g tank after experimenting with it in a 10 gal. In the 10g tank it caused my PH to fall to 6 and it took me weeks of work to get my PH back up. I was wondering if I added Cuttlefish bone or coral to my tank first if it would buffer it enough to keep the ph from falling to much. Current PH in this tank is 7.6. I have mollies and shrimp in there and don't want the PH crash to kill them. Would this work? Is there any other thing I could do if that doesn't work?

 

[wildroseofky]

Forgot to add that I have these PH Up tablets I have been using on my 10 g. Should I add them when I hook up the CO2?

 

[fort384]

CO2 injection does not affect pH in that manner. Something else was at play in the 10 gallon keeping your pH low, assuming you stopped injecting CO2. Once you turn off the flow of CO2 to the tank, pH will raise to "natural levels" (or at least equilibrium of CO2 levels) within a matter of hours.

That being said, the pH drop associated with CO2 injection is not harmful to aquatic life, so long as you aren't injecting more than 50ppm CO2 or so into the tank. Trying to fight it with chemical buffers/etc could potentially have a detrimental affect on your tank. I would not recommend adding anything to the water to fight the drop that CO2 causes.

 

[wildroseofky]

Thanks for the info. The 10 gal was going through a mini cycle. Maybe that dropped the PH? I keep reading that CO2 causes ph to drop though. Maybe not that much. It did finally come back up and has been stable for a few weeks. I have no way to turn the CO2 off at night being that it is diy. Unless you could recommend something. I read a post on plantedtank.com were a guy mentioned something about using a shutoff valve and balloon or bottle to catch CO2 until the morning. I guess you add a shutoff valve to the tubing before it goes into the tank and somehow direct the CO2 into a balloon attached to the tubing. Not sure how to do that yet. I sent him a message asking him to explain it but no reply yet.

 

[Florio]

I would forget the whole balloon thing. There would be so much co2 loss through that material there would be no point.

 

[fort384]

CO2 most definitely causes your pH reading to drop, but what I was saying is it is a very fleeting effect. Once you stop the flow of CO2, the tank pH will instantly start to rise. This pH swing though is different in that you are not going to induce osmotic shock or cause other issues with your fish.

When I ran DIY on a tank, I just ran a bubble wall at night on a timer opposite the lights. This off gases the CO2 from the tank at night, when the plants don't need it (and in fact are releasing CO2 through respiration).

 

[wildroseofky]

Thanks for the replies. I have been looking for some timers. Every time I go to Walmart they are sold out. I found a programmable digital one at Harbor Freight for $10 guess I will order some of them. Then I will have to buy an air pump.

 

[fort384]

Home Depot and lowes usually have timers. Avoid the fish store ones. They put a pic of a fish on the box and charge 5 times as much .

 

[Albino Sick Led]

CO2 doees cause ph to drop, most definitely.

CO2 most definitely causes your pH reading to drop, but what I was saying is it is a very fleeting effect. Once you stop the flow of CO2, the tank pH will instantly start to rise. This pH swing though is different in that you are not going to induce osmotic shock or cause other issues with your fish.

When I ran DIY on a tank, I just ran a bubble wall at night on a timer opposite the lights. This off gases the CO2 from the tank at night, when the plants don't need it (and in fact are releasing CO2 through respiration).

Most definitely CO2 makes your water ph drop. When you run CO2, if not saturated completely, the CO2 excess will not only drop your ph it will react with Hydrogen in the water and can potentially suffocate your fish that you have in there. There are a couple of ways to avoid this though:
1. As mentioned you can run an aerator, this will ensure that your CO2 saturates completely.
2. It is very easy to make your DIY CO2 mixture extremely potent. There is not much yeast needed to make the mixture (max 1 teaspoon per every 25 gal in your tank max). Do not make your CO2 mixture too strong.
3. Worst case scenario, if your CO2 get too too high, do an emergency water change (about 30 %) and run the aerator for the next 24 hours this will bring your CO2 levels back to normal.


Keep in mind with DIY CO2 generators, more than just CO2 is being introduced into your tank, having a natural organic reaction like this means that there are byproducts as well. When Water, CO2, and Sugar are mixed, once reacting for a prolonged period of time this causes a by- product of alcohol (fermenting). Miniscule amounts of this will go into your tank with a DIY yeast/sugar reactor, nothing to worry about though unless you plan on running the same CO2 mixture for more than 3-4 weeks.

Remember local water quality quality plays a huge role in your PH as well, no matter how much your buffer your water, eventually the water parameters are going to be close to your local water supply.

Play around with it and see what your plants and fish look once you finally set up. My advice is get in there and get your hands dirty and see what works for you. If you have any questions, feels free to message me, im well experienced in the CO2/planted tank/Fish realm.

Good Luck

 

[fort384]

It isn't that easy to overdose on co2 so long as you are paying attention to it, especially with a DIY setup. There are a lot of concerns out there about co2 effect on pH and IMO it is overstated and overblown. Injecting co2 does not have the same affect on pH as, say, dumping a "pH down" solution comprised of acid into the tank. I have bred sensitive FW shrimp like CRS in tanks that were running at 6.0 pH and 50ppm co2. If you start creeping up into the 90 to a hundred range then it can cause problems. Reaction with free hydrogen ions can happen at saturation but the tank would be long gone by that point. If anything the threat is more present with a pressurized system if you get the infamous tank dump at the end of a cylinder but even that is extremely rare.

 

[aqua_chem]

There are a lot of concerns out there about co2 effect on pH and IMO it is overstated and overblown. Injecting co2 does not have the same affect on pH as, say, dumping a "pH down" solution comprised of acid into the tank.

Well, it is the same effect, really. Hydrogen ions are hydrogen ions, and the effect on pH is the same no matter what how you mess with it. The fact that we can swing the pH of our tanks by more than one point of pH on a daily basis without effecting livestock is, in my opinion, a statement of the completely overblown danger of pH in general, in that people tend to attribute to pH what should be blamed on CO2 concentration, TDS, KH, etc.


As far as CO2 overdose goes, this is why it is highly recommended to have a drop checker whenever you're using CO2, at least in the initial stages when you're getting into routine and figuring everything out.

 

[fort384]

I suppose in a strict sense, you are correct - pH is pH. My point is that we are talking about injecting a gas into the water column that can off gas rather quickly, even after dissolving in the tank. It is far less permanent than other chemical means of lowering pH. It doesn't take but a few hours, generally, and especially if you have surface movement, to lower CO2 concentration back to equilibrium with air.

 

[phin]

I'd like to jump in.

18 gallon tank. Since I've set up my DIY CO2 (2x124oz gatorade jugs) mix is 2c sugar + 1/2 tsp active dry yeast, water filled within 3 inches of the top of the bottle. I don't change the mix very often, as my bubble count is pretty consistently high. Right now I'm getting over 3 bps. I last changed one jug about 9 days ago and the other about 3 weeks ago.

My drop checker went yellow. tank parameters are: pH 6.5, KH 3, GH 6. Fish don't seem to be showing any signs of distress, but I'm getting a lot of CO2 for my tank.

How long is the solution in the drop checker good for? I think its about 3 weeks old. Does it go yellow when it wears out?

 

[aqua_chem]

No, but 3 bps with good diffusion efficiency and minimal agitation could certainly give you yellow levels in your drop checker. I usually changed my DC fluid after about a month.

 

[phin]

I've got a penguin biowheel 125 turning, as well as the outflow from my canister aimed toward the surface. No spashing, but some good surface movement. Plants are taking off. Wisteria has grown about 6" in two weeks. Water sprite has almost doubled in the same amount of time. I put some bushy pondweed (Najas spp.) in that I pulled out of a pond, and thats taking off too. All my crypts are coming back, but slowly. All in all my DIY CO2 has been a big success.

I'll keep the drop checker solution in there for another week or so.

 

[wildroseofky]

I am going to start my CO2 tomorrow. I made a diffuser and have to let the glue dry around the tubing. I used super glue but I want to give it at least a day to cure. I found that the super glue works best as the silicone will not adhere to the tubing. The glue I used is Fix-All Adhesive from the original makers of Super Glue. It has worked well on anything I have used it on. I am gong to use a 3 liter juice jug with a smaller bottle as a bubble counter. I found a way to shut off the CO2 at night but I am not sure how well it will work. You put a shutoff valve right before the tubing goes into the tank. Then you add a 3 way splitter before that. Then put a balloon on the end of one of the splitter arms. use a rubber band to make sure the balloon mouth is air tight. How it works is the CO2 gets directed into the balloon when the shutoff valve is closed. The balloon holds the extra CO2 during the night. In the morning you just open the shutoff valve and the saved CO2 is used up during the day deflating the balloon. At night repeat the process. No wasted CO2 and the tank doesn't get over saturated. I don't know if it works yet because I have not tried it but I am planning on it. If the balloon pops, no big deal. The guy I got this from said you could you an extra bottle too but I wouldn't trust that. The balloon seems safer.

 

[fort384]

Balloon definitely seems safer than an extra bottle. I have heard of people blowing up their reactors by shutting them off and forgetting to turn them back on. I would think the water/yeast/sugar mix would not be a fun cleanup.

Post some pics of the system once it is up and running. While some of the CO2 will leak through the balloon walls, it seems like a good way to go to conserve at least some of the co2 produced in the reactor.

 

[aqua_chem]

Isee some obvious problems with your setup.

1) You wont be able to build any pressure at all. This setup will only work with a zero-pressure diffusion method, so basically either a reactor or a less-that-desirable diffusion method.

2) Entirely possible you'll fill up your balloon between photoperiods, where it will just shoot off or pop.

3) When you turn it back on, you'll inject 2-3x the total amount you'll inject during your entire photoperiod instantly. This could be really dangerous to your livestock.

 

[wildroseofky]

I am going to test it in my 10 g fishless tank first. Aqua Chem has some valid points. The guy I got this from swears it works in his 40 g. It will be this weekend before I can get a shutoff valve. No place around here had one. Got every thing else and will post pictures tomorrow.

 

[fort384]

Isee some obvious problems with your setup.

1) You wont be able to build any pressure at all. This setup will only work with a zero-pressure diffusion method, so basically either a reactor or a less-that-desirable diffusion method.

2) Entirely possible you'll fill up your balloon between photoperiods, where it will just shoot off or pop.

3) When you turn it back on, you'll inject 2-3x the total amount you'll inject during your entire photoperiod instantly. This could be really dangerous to your livestock.

1. It will be able to build pressure, depending on the balloon that is used.
2. Definitely a possibility - that would be my biggest concern with it.
3. I don't think it will be that high. There will be loss here. It would hinge on the diffusion method though.