Best way to diffuse CO2 into Aquarium?

Jim Conklin wrote:
Folks I think I'm having a problem getting CO2 to diffuse into my tank.
My well water right out of the tap is very soft and acidic: about a pH of
6.2, a KH of 80ppm and a GH of 75. (Perfect for Discus, which I keep.) I
have a small CO2 tank connected with silicon tubing. I put the outlet tube
into the inlet of my Rena Filstar canister filter. I give the 55 gallon
tank about 12 hours of light with two 65 watt compact flourcent bulbs. But
I'm still troubled by 'black-green' algae and minimal plant growth. I keep
the water at 85F. I fertilize regularly with Trace and Flourish and keep the
Nitrate level at 20ppm.

I've tried all different types of plants and while they survive and
grow a bit, there is no growth such as I see in pictures of other hobbyist's
tanks. Any advise or suggestions on how to get the CO2 to stay in the water
or what I could be doing wrong is appreciated. From the specifications
above above I'd think the plants should be growing out of the tank! Thanks
for any help.

JC

you have a few things going on, one is a lack of K+ and likely NO3.
It's a discus tank, so doing weekly water changes, say 60% will help.
You will not have much build up of NO3 this way.
The light is not particularly high, so the CO2 needs to be addressed
but it should not be too tough to get that part right.

The BGA, the algae you have, you need to kill/remove what is there ,
then start dosing KNO3.

I do not know how many times folks have claimed they have 10-40ppm of
NO3 then they dose the KNO3 and ther BGA goes away and their plants
start growing.
We have dosed high levels of K+ with K2SO4 and still had BGA, so it's
not that part.
NO3/PO4 test kits are notoriously inaccurate.
Lamotte and Hach tend to be fairly accurate when compared to a known
series of standards. You can calibrate the cheapy test kits if you make
the standards yourself.

I'd do this:
Clean the tank good of the BGA, clean the filter good.
Disturb the substrate a bit and get any muck up.
Do a 60% water change.
Add KNO3 at 1/2 teaspoon.

Black the tank out with a couple of trash bag layers
Tank needs covered/no light for 3 days, turn off the CO2 and turn the
filter to cause the surface movement to increase.

You can feed fish and peek in etc,

After the 3 days, remove and hook the CO2 back up, do another 60% water
change, add
1/2 teaspoon of KNO3 and about 2x a week from then on.
Add 1/8 teaspoon of KH2PO4 2x a week also.
Add a trace mix(Flourish etc) at 10mls 2-3x a week.
GH booster, you may need this.

See www.gregwatson.com for these chemicals, they are very cheap and
will last a year or two.

CO2 reactor, I have a diagram on my web site (it's on the public side,
not the subscriber side) on how to make a nice looking, 2$
diffuser(plus a rio180 powerhead, 10$ on line), you can also make a
cheap PVC in line reactor also(See RexGrigg's site-search google etc)
but the internal version is very easy to use and does the job for DIY
or gas tank CO2.

The other option is adding SeaChem Excel(1.5-2x their suggested
amounts).

That will take care of most of the issues you have and give you the
pearling and weedy plant growth the rest of the plants folks have.

Regards,
Tom Barr


www.BarrReport.com