Co2 Noob Questions

[Psylant]

Hi everyone,

I'm an experienced hobbyist, but not so much with plants lol. I just started my first decent attempt at a planted tank, as some of you may know. It's a 90g dirted tank, fairly heavily stocked by planted tank standards. I'm starting to get some algae growth and have dialed back the lights (Finnex Ray II 7k) to about 6-7 hours a day. I think I might want to go down the road of buying/building a pressurized CO2 system but it seems a little daunting and expensive. I think I would like a cylinder I wouldn't be refilling more than about once every 2 months at the very earliest. Function is more important than looks, to me. Does anyone have some tips on how to save money, where to buy equipment, good techniques, etc.? I've read a little about it, but a lot of it is greek to me and there seems to be a lot of different methods out there. Any help would be appreciated.

Edited July 7, 2014 by Psylant

[jvision]

A 10lb tank will last over a year before needing to be filled. If you get a tank that size and one of the 3-in-1 Reg units you'll probably look to spend around $250.

[Psylant]

That's what I figured. That's a little steep but manageable. Do you have any preferred models for equipment, or places with good prices to buy it from?

[IronChefItaly]

With or without co2 I'd recommend using Excel Flourish. I run my lights for 9 hours a day, co2 during this time and with 2-3 doses of excel a week I've managed to keep algae out. I run a smaller paintball co2 system so i can't help you out with full size equipment.

[Psylant]

I'll have to experiment with dosing after I get the CO2 up and running. I mostly get insane amounts of green spot algae, which I've read is usually due to low CO2.

I don't think paintball cylinders will work for me unfortunately. Thanks for chiming in.

[Pteronarcys]

I would recommend getting a CO2 cylinder and diffuser. With a 90g dirted tank, you have lots of nutrients leeching out from the soil. If you have lots of light, you have 2 of the main components to a great planted tank. Without CO2 the plants will not photosynthesize as efficiently in comparison to algae. You will constantly have algae issues without balancing all the needs of the plants.

Also have a good clean up crew: oto cats, nerite snails, and algae shrimp (if you don't mind snails that breed: ramshorn and Malaysian trumpet snails) . Stop with those if you want to keep small shrimp in your tank. If you don't care about shrimp, go with some other algae eaters like bristle nose pleco, sailfin mollies, and Siamese algae eaters. Mollies and siamese algae eaters will eat shrimp.

For a 90g I would not use paint ball canister set ups. Those are mostly for nano tanks, like the fluval or ADA tanks. The larger cylinders are much better and last a lot longer. Here in Calgary I go to Recharge center to fill my tanks. I have an extra cylinder to swap out when the other runs out.

Now getting into CO2 can be tricky. To get that magic 30ppm of CO2 you need to know your water's dKH (alkalinity or carbonate) and pH. I have the Hanna alkalinity digital meter, but you can use liquid test kits as well. I also have a pH controller that has a probe constantly in the water to read the pH. This also turns my solenoid on my CO2 regulator on when pH rises and off when it reaches a point a set it for. The more CO2 you add the lower your pH goes. Once you know your dKH you can look on a chart to determine what pH you need, such as this one: http://www.littlegreencorner.com/tipsdropchecker.html

The kH of the water I tested yesterday was 7.8. Looking at the chart I can see that at a pH of 6.9 I will have approximately 30ppm CO2. Because Calgary water parameters change throughout the seasons (spring flooding/run off, adding more chlorine to counter higher bacteria levels, etc) it is good to test a few times a month for any changes. There is also a website for Calgary City that list water parameters and it updates them.

I have the aquariumplants.com regulator that has a built in digital bubble counter. I can set how many bubbles per second I want added to the tank. I also have the CO2 running through a reactor on my canister filter's return line to dissolve the CO2 into the water, thus preventing lost CO2 bubbling to the surface from an air stone or other diffusing method. http://www.aquariumplants.com/CarbonDoser_Electronic_Co2_Regulator_p/co2.htm This regulator is great because with normal solenoids, when the cylinder gets low, they can release remaining CO2 in a cylinder quickly and gas all your livestock. This means all animal life is dead. Seen it many times with friends, at work, and had it done to my tanks. Since this regulator has a digital bubble counter, it can only release one bubble at a time. If it is set for 2 bubbles per second, that is all that will release regardless of cylinder pressure.

When you first start using CO2 you want to lower pH to the ideal setting slowly over several days. pH is a logarithmic scale and going from pH8 to pH 7 is a huge shock to animal life. Most will die. If you over shoot and add too much CO2 livestock dies. That chart I posted earlier in my response shows the ppm of CO2 if you drop the pH too far. Going higher than 30ppm and fish/shrimp/snails start stressing and as you go higher, their is too much CO2 and they die.

The other issue with CO2 (at least with tap water that is high pH like Calgary's pH 8 water) is that with tap water with high KH and pH, it is naturally buffered to want to be at pH of 8ish. This means if your CO2 runs out and you are not on top of it, the pH can change back to 8 once the CO2 has all left the water. Again large pH change=dead animals. I didn't have much issues with this in Houston when I lived there. Water parameters were close to 7pH and KH of 4-5. CO2 ran out there, parameters didn't change much.

I have had a lot of trial and error, mistakes, die offs, etc over the years. But I learned from each. I bought books, read a lot online, made more mistakes, researched why things were happening, discovered new products, etc. While planted tanks can be easier if you do low light or use the "weeds" like elodea or use crypts, ferns and mosses, you start to get addicted and want more. Cooler plants, orange plants, red ones, lush carpet plants, etc. I have built up my aquarium gear over the years piece by piece. Upgraded bits. But the good thing is most of what I have now I will always have or they will last a long time.

I hope I don't scare anyone off planted tanks. They are awesome and once you know what to look for and how to do it, its not that hard.

[Psylant]

Pteronarcys, I have already stocked the tank with fish. It's fairly "overpopulated" by planted tank standards. Rainbowfish, SAE, Roseline sharks, cories, and snails. Thanks for the abundance of information.

What I was thinking was to start off extremely slowly injecting CO2 to try to keep the pH more steady. I don't think I'll ever dose that much. It's more of a fish first, and plants are second sort of tank. I just want to give the plants a little something extra and get a little healthier and lusher growth.

You seem like you have a lot of money tied up in your setup. I was looking to spend about the price of just the regulator you linked! I am a little flexible on the spending though... I was just going to get the basics, a cylinder, regulator, needle valve, etc. If you refill the tank before the "dump" occurs, aren't you in the clear? Also, if I'm not dosing high amounts of CO2, isn't the end of tank dump considerably safer because the pH would be higher and more buffering capabilities would exist in the water? I've also read that there are some regulators out there that do not dump at all such as yours. I'm in no way knowledgeable about this topic (hence this thread) so excuse my ignorance if these are dumb questions.

[Pteronarcys]

Ya I started planted tanks with yeast CO2 systems in coke bottles. Slowly over the years I have grown in technology and getting better gear. It definitely didn't happen all at once. I also made sure that things I spent money on were on sale, or I got at discounts/used store credit. Many stores will give you credit for plants and if you have good growth, each time you trim you bring in the trimmings and get credit. This often paid for all my fish food, ferts, and went towards buying new gear. Most LFS don't have proper set ups for plants and quickly their plant stocks look like crap. They like when people bring in nice looking plants and usually offer credit. Though depending on the store they may not give credit or it will be negligible.

I am off topic (I tend to ramble). The regulator I posted does not need a needle valve. The digital bubble counter acts as a solenoid and it is built into the regulator. Simply attach it to the cylinder and set how much bubbles you want and your good to go. Other regulators the needle value acts wonky with lower pressures as the cylinder is close to empty thus dumping the rest of the CO2 quickly. This causes the CO2 concentration to jump very high (100ppm or higher) and lower the pH quickly in the span of a few minutes. Even if you are just using a bit of CO2 like you said, dumping quickly will gas the animals and kill them off. I used to work in a neuroscience lab as a research tech and one of my jobs was to gas the mice we didn't need with CO2. They were dead in 20sec. I hated doing that.

Though if you keep check on the pressure in the cylinder and refill it before it gets low, then you are golden! I discovered this aquariumplants.com regulator when researching CO2 dumps that had happened twice to me and was the second time I had lost all my fish and shrimp (I was quite frustrated). Sometimes you get busy and don't check pressure daily and come home from work to see a tank full of death. Not a good feeling. Many small funerals to attend around the toilet bowl. Since I got that new regulator.. never had that issue again and I recommend it to anyone that uses CO2. I purchased my cylinders from them too (even though they are american company). I like having the second one ready to switch because refill place is on the other side of the city from me. Seems all the CO2 places that will let non commercial people come to fill cylinders are down in the industrial area of Calgary.

So if you get the regulator and cylinder, all you need from there will be pH test kit, KH test kit (or alkalinity test kit), air tubing, plastic bubble counter (to see how many bubbles per second), and some sort of diffuser. Some people use air stones that are designed for CO2 that creates tiny bubbles, others like ones that trap the bubbles and they go back in forth in a sorta maze to increase the time the bubbles are in contact with the water to dissolve. You can also attach the air tube to a powerhead and this causes the bubbles to be broken up into small bubbles in the powerhead current.

If you have issues with the plants here is a nice chart to let you know what might be wrong with them. It also gives you lots of info on CO2 in plant tanks http://richardbrown81.hubpages.com/hub/co2-in-a-planted-aquarium

[Pteronarcys]

That last site I posted has the KH, PH, CO2 chart in it, but it has the colour coding backwards. Yellow is too much, red is not enough. Basically over 30ppm is too much and under 15ppm is not enough. There are some plants that can take carbon source directly from bicarbonate in the water and thus don't require CO2 injection.

Plants are a carbon based lifeform and to grow they need more carbon. The only way plants can do that is by taking in carbon through photosynthesis. Since they are a more complicated life form than algae, algae will out compete plants if the plants don't have all the right conditions met for optimal growth.

While you add CO2 don't have a lot of breaking of the surface water with powerheads and don't add O2 with a bubble wand during the day. Picture what happens to a pop can when you shake it up... all the CO2 releases quickly. A little rippling of the surface is fine. Canister filters are best because they take and return water beneath the water surface. Hang on the back filters create water falls and most CO2 is lost.

Lastly, don't forget with CO2 that plants stop taking up CO2 at night and start to breath in O2 and give off CO2. It is part of what is called, the Calvin Cycle in plants or the dark cycle. So basically in a heavily planted tank, plants add to the CO2 at night and reduce O2 levels during the night. Without a CO2 controller, it might be wise to turn off CO2 at night and have oxygen added through a air pump and bubble wand. That way you don't get excess CO2 at night and have die offs.

[Psylant]

I have a Fluval 405, Aquaclear 110, an airstone, and also a maxijet powerhead on this 90g tank. I was going to feed the CO2 into the powerhead intake to disperse in the tank. I intended on running the air stone at night, and cutting off the CO2. Is my thought process wrong in assuming that since plants are releasing CO2 at night, that this would help offset for the CO2 pressure being cut off at night, in terms of pH? I read a very detailed study about HOB filters and CO2 losses were fairly negligible (about 15% if I remember right?). I'll try to find it again if I can when I have the time to search.

If I were to cheap out and get a low grade regulator that causes a dump, doesn't the pressure on the gauge slowly diminish and give several days/weeks notice pre-dump? I really don't want my fish to get nuked, but if all that requires to not happen is check the gauge every few days that's totally fine with me.

[Pteronarcys]

Ya the gauge will show a decrease in pressure over time. Though these things tend to wait till your busy and when you haven't looked at the gauge in a few days. I am a teacher and during the year I often get home at 7 and then have a lot of grading to do or planning. It is easy for me to get swept up with stuff and let things slip. That or I see the cylinder is getting low but I can't seem to find the time to go get it filled because by the time I get out of work the places to refill are closed.

I am not sure how much CO2 plants give off at night and how much this affects pH. I just know that when I run out of CO2 my tank goes back up to pH8 rather quickly. Though I am sure this all differs depending on the water you use in the tank (RO, distilled, tap, etc.). It is best to just do some tests when you first start setting things up.