Considering Pressurized CO2 - A Few Questions

  • #1
About a month ago I decided I wanted my 20 gallon long to be more densely planted. After adding several new plants, I upgraded my lighting, started dosing weekly with liquid fertilizers, and began adding the recommended dose of Excel daily. While I have had some growth, the plants don't seem to be doing exceptionally well and I have started battling hair algae on the slower growing plants. I have come to realization that I may have to resort to pressurized CO2 to get the results I want.

Here is my current setup:

Filtration: AquaClear 50
Substrate: Seachem's Onyx Sand
Circulation: Hydor Koralia Nano 240
Lighting: 36watts T5NO
Dosing: LeafZone and Flourish Comprehensive Weekly, Excel Daily
Inhabitants: Pristella Tetras, Cories, Nerite Snails
Plants: Java Fern, Anubias, Water Wisteria, marimo moss balls, Narrow Leaf Saggitaria, rotala rotundifolia, Crypt WendtiI Bronze


From my limited research, it seems that the regulators from Green Leaf Aquariums are highly recommended. I am considering the paintball regulator with the built in bubble counter and check valve. From what I've read, a paintball cylinder will last about 2 months on a 20 gallon tank. Please correct me if I'm mistaken.

I know the next thing I'll need is an in-tank diffuser. Not sure if I'll need the 45mm or 60mm. Really dumbfounded on this one. Also, how often do you need to clean the diffuser? Green Leaf recommends you have two on hand so you'll always have a clean one ready. Is this really necessary?

Lastly, I was looking at the drop checkers on their site. Should I invest in one? I highly doubt I'll ever push the CO2 levels to my tank's limit. If one is needed, which one would you recommend?

Also, a few other things that I'd like to clear up:

- How do you know where to set the working pressure?
- When should I be injecting CO2? I've read to start an hour before the lights come on and end an hour before they go off. Is this right?
- Will I need to increase my fertilizer dosing schedule? Right now I'm adding liquid ferts once a week.

Sorry for all of the questions...thanks!
  • #2
I use 5lb co2 tank. works like a charm. its big but if you hide it, it works 6-9 months. refill here is $10. I buy my diffusers online via china. cheap and it still works fine. co2 drop checkers, I purchase one from china too. also cheap but solution should be purchased somewhere else.
  • #3
Looking at your plant list, none of those plants need CO2 injection. I would imagine you may see slow growth due to nutrient deficiency. You probably need some more macro ferts. CO2 injection can be expensive and it one more contraption to need to run, and set just right so as to not out gas your fish. Before I invested $200 in a decent CO2 system I would try upping the macro ferts to see how things go. Remember too, that many plants like the ones you have, are just slow growing by design.

With that said if you are dead set on CO2 injection I would recommend looking up some info on planted tank. They have a lot of plant experts over there, also many people sell used or built to suit CO2 systems that should save you money. They would be able to advise you the best setup etc. Here are some links that should help you out....

Basics of CO2 system setup....

Here's a thread about building your own CO2 system...

Do some good searching there on planted tank and you should be able to find out a lot of stuff. Check the "equipment" section for info about CO2 systems and check the "for sale/trade" section for people selling used equipment or systems.
  • Thread Starter
  • #4
Dolfan, thanks for your reply. I'm not dead set on CO2 injection but there is definitely an imbalance in my tank. My stem plants are alive but seem to be stunted. I've noticed very little growth in the past month. Also, hair algae is becoming a problem. I assumed this was due to inconsistent CO2 levels. I was hesitant to increase fertilization with the fear that would make my algae problem worse.

You mentioned adding more macro ferts. I'm currently adding the recommended dose of comprehensive and leaf zone weekly. What fertilization schedule would you recommend for my tank? Thanks.
  • #5
Please note that T5NO is not high light. The color spectrum of the bulb may be more at fault as is also nutrient balance. Also you might want to up the dose of excel to help kill algae but watch out for melting plants.
  • #6
Matsungit is right, you may have some lighting issues as well.

As for ferts, I know that Flourish Comprehensive is very low in Macro ferts (Nitrogen-N, Phosphorus-P, and Potassium-K), not sure about Leaf Zone. I assume its probably similar. I would suggest you use some NPK specific ferts like Seachems line of N, P, and K separately or if you are wanting to get a bit more serious and save money in the long run, check out dry ferts. Greenleaf aquariums sells the Estimative Index and PPS-Pro packages very cheap. Get the package that has the bottles included, as really they are the same package just about, its more in how you dose with them. You may want to check out the EI dosing method pioneered by Tom Barr. You may need to modify and lessen the amounts a bit since at the moment you don't have CO2 and may have low-mid light.

Basically EI (Estimative Index) is a dosing system where you supply a bit more ferts then the plants need, so they never run out of food. This makes it where the limiting factor has to be either light (which can easily be adjusted) or CO2 (which can also be adjusted). It is recommended you do a 50% water change once a week so as to reset the system and remove any extra ferts that the plants didn't use that week. If you need to adjust the lights, you can lengthen or shorten the photo period. If you need to adjust CO2 you can add more or less Excel, or invest in a CO2 system if you want. I think it's easier to run a low tech system with easier plants (like yours) with just some Excel.

Do a google search on "estimative index". Check out planted tank as they have a lot of plant specific info. Tom Barr the creator of the EI method is on that forum, his name is Plantbrain, so look for his posts, he is a plant genius. He has used the EI method for high and low tech tanks with great success.
  • #7
Hair type algae are usually caused by too little Co2 or lighting. Lighting should be on a solid 6-8 hours a day and in the color temperature of 5000k-10000k. With your new lights you are around moderate light with the height of your tank. How it works is if you increase light then co2 and ferts may need increased as well. I would slowly increase your Excel dosing and remove as much algae as you can. See what that dose. Next thing would be to increase ferts. You make adjustments slowly and observe. It can sometimes take a few weeks. Just be patient.

Anubias are slow growing plants and if put in stronger light most often will get algae. Anubias do best either shaded by other plants if lighting is a bit strong to keep algae at bay or kept in a low-light setup.
  • Thread Starter
  • #8
Thanks everyone for your help. I do not think lighting is an issue. The fixture rests right on top of my tank which is only 12 inches high. 36 watts of T5NO should give me moderate lighting. I'm also using 6700k bulbs. I'm going to stick with the Excel as my carbon source for now and will slowly increase ferts to see what happens.

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