CO2 advice?

[Delphinus]

I want to add CO2 to my planted freshwater. Mostly anubias right now, some other various plants, and some java fern. Want to go with more eventually. Tank is a 30g, current lighting is 4x20W NO (daylight tubes).

Was thinking about starting with 6-10 bubbles per minute. Is that a reasonable starting point? I don't want to shock the system. What are things to watch out for?

I can measure my pH plus I do also have a CO2 test kit, so I should be able to monitor the levels but I don't know what are good values to use as targets.

[trilinearmipmap]

Measure your pH and kH then calculate your CO2 level using the graph here (http://www.sfbaaps.com/reference/table_01.shtml).

A good goal CO2 to aim for is about 30.

I suggest DIY CO2 for this size of tank.

What worked well for me is run DIY CO2 for 3 months or so, when the plants have grown in well discontinue the CO2 and you will have a nice planted tank that doesn't need too much pruning.

The amount of bubbles per minute depends on how you are diffusing your CO2 as well as surface agitation in the tank. For DIY CO2 you have no control over bubbles per minute. For CO2 injection with regulator and needle valve for that size of tank you could start with one bubble every 5 seconds, then adjust the rate up gradually depending on your CO2 level, allow it several hours to a day between adjustments. On my 75g 1 bubble per second works well.

[trilinearmipmap]

And if you want plants I can send you some for shipping cost only, if in return you can send me some soft coral frags in a few months when I get my reef going.

[Richer]

I would personally suggest a pressurized system for any tank. Even though a pressurized system is a lot more expensive in terms of intial costs... in the end, it will more than pay for itself. My 5 lbs CO2 tank lasts about 6 months before it runs out (on a 70gallon tank). Refills cost 10 bucks. I did have a DIY system on an old 15 gallon tank that I had... it was a pain. I had to replace the bottle every week, and the CO2 output was difficult to control. Plus the smell of the CO2 generator wasn't all too pleasant neither. Using a jello based recipi would increase the lifespan of a CO2 generator by a couple of weeks. If I forgot to replace the CO2 generator, or if I went on an extended holiday, my tank would suffer. If you do decide to try out the DIY method on your tank, I would suggest 2 CO2 bottles, 1 may not generate enough CO2 for a 30 gallon tank.

I would bother using bubbles/second as a baseline for CO2 injection. As said before, the amount of bubbles/second needed for a tank is completely dependant on surface aggitation, plants, etc. Using a pH and KH table is the best way to go about it.

-Richer

[StirCrazy]

unless you are upgrading to more powerful lights and getting plants that need higher light I wouldn't waist your time.

as for DIY CO2, I hate it, made 4 units and not one worked right. go pressurized if you are going to do it.

just remember that CO2, light and fertilizer (food) are all a balancing act, if you max out 1 of them it won't matter how much of the others you add nothing will change.

for example, if you add CO2 and food, but have low lighting the plant won't have enough energy to utilize the extra CO2 and food, so you will hit a plateau until you increase the light, and so on. the problem I have on mine is food, I can add my home made fertilizer like it is going out of style and can't keep a nitrate level in my tank :rolleyes: heck I can't even grow algae in that tank.. wish my reef worked the same :mrgreen:

Steve

[trilinearmipmap]

I can't agree with the comments on DIY CO2. Currently I have 3 plant tanks running: one pressurized CO2, one was DIY CO2 switched to no CO2, one has never had CO2.

For tanks up to the 30 gallon range DIY CO2 is simple easy and cheap. I have never had a smell from DIY CO2. Every two weeks refill the bottle with water/yeast/sugar. As far as the system not working right, it's pretty simple, drill a hole in the cap of a 2 Litre plastic pop bottle, run airline tubing through the cap, silicone it in place.

To me pressurized CO2 for a small tank is overkill. For tanks 50 gallons and up it makes sense.

[Richer]

I wouldn't call a pressurized system on small tanks as overkill. As long as the method of reaction is good, a 5 lbs CO2 tank on a 30 gallon tank can last for quite a long time. All you need to do is watch CO2 input for a couple of weeks to make sure its stable, and that your CO2 concentration is at the level that you want it to be. After that, its basically a leave and forget kind of thing.
Don't get me wrong, DIY CO2 will work just fine for smaller applications. Heck, I had it run on my 15 gallon tank for a year. However, I can get lazy... and if there is a more efficient way at doing something, I'd go for it. The frequent maintanence that my DIY CO2 generator needed just wasn't for me.... so I switched to a pressurized system. Good thing too, because shortly afterwards, I upgraded to a 70 gallon tank :biggrin: .

-Richer

[Delphinus]

Thanks for the comments. I guess I should have mentioned, but before I had actually asked the question originally, I actually did already have a spare small CO2 cylinder that I just wanted to put to some use.

For now I've just put a small bubble rate going. About 50 bpm is what it's at. It barely bumps the pH down (without it the pH is about 8.5, with it ... maybe 8.3). My water is dang hard (not using RO in this tank .. should I?)

Haven't adjusted fertilizer, haven't added iron or anything like that, no lighting adjustment as of yet. But the anubias have started growing like there's no tomorrow so something's happening.

My next issue to resolve before I get into fine-tuning the CO2 or the fertilizers is to fix my lighting problem. I currently have 4x20W NO lights over this 30g tank, that should theoretically yield me 2.7 wpg but in reality it's nowhere near that since one of the pairs seems to have an issue (ballast maybe?) where the lights stop lighting after about 1 month of use. I haven't decided whether I want to to fix the current setup, replace it with PC maybe, or whatever. In a separate thread I had asked about switching to 150W DE halide (since I have a DIY fixture and a lamp and a ballast, all sitting around unused anyhow, that could get put to some use), but I seem to recall I had been more or less talked out of the idea. I dunno .. what do you guys think? Stick with NO, go to PC, or to heck with it and go with the 150W DE? The halides are the cheapest option believe it or not, since all the equipment is there. The other two would involve a purchase of some kind (new ballast, or new fixture, or new DIY supplies, etc. etc. etc.)

[StirCrazy]

I thing a MH would be overkill if you want to keep your lower light plants also. a friend of mine has a tank that puts mine to shame and he is running el cheepo daylight PC and it is amazing.

Steve

[Delphinus]

Actually I kind of wanted to get into a few red leaved plants .. aren't those more light-demanding?

With that said, I'm happy to forgo MH over my FW tank, if something like PC will do the trick. I just haven't saved up for the ballasts and stuff yet, so it might just have to wait a bit.

[Canadian Man]

Actually I kind of wanted to get into a few red leaved plants .. aren't those more light-demanding?

With that said, I'm happy to forgo MH over my FW tank, if something like PC will do the trick. I just haven't saved up for the ballasts and stuff yet, so it might just have to wait a bit.

I had some red leaved plants in my fw tank a year or so ago. At that time I had co2 (yeast and sugar method) and the same 3 bulb flourescent light's that I have now. The plant's grew great! Once they reached the top of the tank the red color was outstanding!

[trilinearmipmap]

If you want high light, PC will be more than adequate. For a 30g tank one length of PC bulbs will be fine.

I suggest you check out www.ahsupply.com if for an excellent pc setup with 6500K bulbs. Depending on the length of your tank either a 96W (36") or 55W (24") bulb would do the trick. I have 4 x 55W on a 75g tank and I am looking at downgrading my lighting because the plants grow faster than I can prune them.

I do not suggest MH due to heat issues and due to nutrient imbalance/algae issues.

[Chad]

I have 1x 55w PC 10k on my planeted 25gal. I do zero suppliments, no CO2 .. nothing.. the plants get over grown within a week. I have one that is actualy blooming right now. :biggrin:

At one point I did the DIY CO2. It seemed to help, had the little O2 bubbles coming off the plants, always a good sign. But the growth rates were about the same as it is now with zero CO2 additions.

Just my thoughts.. :biggrin: