Not enough CO2? - The Planted Tank Forum
LinkBack Thread Tools Display Modes
post #1 of 5 (permalink) Old 01-03-2005, 05:23 AM Thread Starter
PTrader: (0/0%)
Join Date: Dec 2004
Posts: 50
Not enough CO2?

My tank has been set up for about 2 weeks, and I've been adding CO2 for 3 days now.

I just tested my water and got the following results:

pH = 7.4
GH = 6.7
kH = 3.4

That gives me a pathetic 4 ppm for CO2! I'm bubbling 48bpm from the compressed tank into my 50 gallon tank.

Straight from my tap the water is pH=7.8, GH=7.8, kH=3.4.

Do I need to double the amount of CO2 I'm putting in? That seems like an extreme amount of CO2 for a 50 gallon tank. There is no surface agitation, but the only thing pearling is the algae on a piece of wood.

In case the tests are off (using Hagen), I've got a new Aquarium Pharmaceuticals kit coming tomorrow so I can retest then.

One thing keeps gnawing at me though: There is 100% absorption in my external reactor, yet when I first tried it on the hagen ladder the bubble size did not shrink at all. Any chance my tank is full of air and not CO2?
bigfishy is offline  
Sponsored Links
post #2 of 5 (permalink) Old 01-03-2005, 01:33 PM
Planted Tank Guru
Rex Grigg's Avatar
PTrader: (65/100%)
Join Date: Dec 2002
Location: Portland Orygun
Posts: 9,600
Pearling or lack thereof doesn't mean much.

It's strange that you did not see the bubbles getting smaller with the Hagen ladder. But if you were injecting air I doubt you would be getting 100% diffusion in your external reactor.
Rex Grigg is offline  
post #3 of 5 (permalink) Old 01-04-2005, 07:41 AM Thread Starter
PTrader: (0/0%)
Join Date: Dec 2004
Posts: 50
I upped the bpm to 74 and lowered the spray bar to point down. The surface of the water is now stagnant. Is this what you guys normally do?

My pH is now 7 which indicates a CO2 level of 10ppm. I'd like it higher, but I'll wait till I start adding baking soda to buffer the pH. Several plants began to pearl today. Most notably the watersprite, sword, and hairgrass. I also have a red plant which I will need to post for identification.

Something interesting I thought I'd mention: In searching older posts I came across the same symptom I had tonight. When I shut off the CO2 there were still tons of bubbles left in my reactor which wouldn't dissolve. Turns out that my Rotala had been pearling right beside my filter intake and the O2 had been sucked directly into my reactor (which is on my pumps intake). Stood there frustrated and dumbfounded for a couple of minutes to figure out how to rid myself of these bubbles without dismantling the whole setup. Simple solution: turned off the filter and pressed the prime button. This forced all the accumulated O2 out the pipe. Turned the filter back on and viola!

I assume this would work for the Eheim pro-II's as well. Just wanted to say that this AQTX filter is really sweet.

Wanted to add: Even though there's a huge Eheim following, I'll be proud to be member #1 of the reformed Eheim Pimp Club. Just need to figure out some sort of 12 step program....

Last edited by bigfishy; 01-04-2005 at 07:57 AM. Reason: clarification
bigfishy is offline  
post #4 of 5 (permalink) Old 01-04-2005, 01:12 PM
PTrader: (0/0%)
Join Date: Mar 2004
Posts: 493
Just curious bigfishy how you came up with your GH and kH numbers? I have not come across any test kits that read to tenths of a degree.
TeeItUp is offline  
post #5 of 5 (permalink) Old 01-04-2005, 07:41 PM Thread Starter
PTrader: (0/0%)
Join Date: Dec 2004
Posts: 50
No, the test isn't accurate to that degree. The Hagen manual says to multiply the ppm by 0.056 to get degrees hardness. Therefore my only possible results would be 2.8, 3.4, or 3.9(with 50, 60, 70ppm) for kH.

Regarding adding baking soda: Is it correct to add 1/2 tsp to 100L for each degree kH you want to raise it by?
bigfishy is offline  


Quick Reply

Register Now

In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome