testing c02 levels - The Planted Tank Forum
 
LinkBack Thread Tools Display Modes
post #1 of 5 (permalink) Old 01-14-2010, 03:12 PM Thread Starter
Planted Tank Enthusiast
 
PTrader: (33/100%)
Join Date: Dec 2009
Location: Michigan
Posts: 632
testing c02 levels

I posted this on another forum without much response.... wondered if anyone here could help me out... it was 2 posts.


first post:

I found a site that had a calculator where you plug in PH, KH, and it spits out your c02 ppm... anyone know how accurate this method is?

http://csd.net/~cgad...nt_co2chart.htm

I had a PH of 7, and KH of 4, so my c02 was 15ppm... Ofcourse, 15ppm doesn't mean a WHOLE lot to me.. I know it's not very high... people were saying crank it up to 50ppm to stave off algae... Can anyone tell me if that is going to help my plants much? I setup a DIY c02 deal and have the bubbles going through my powerhead for diffusion. Seems like it is working ok, but I may need to lower my powerhead as there is a lot of surface agitation and I know I'm losing c02 because of that. Also, I know that the bubbles aren't having a huge chance to disolve, even though they are chopped into reallly fine bubbles by the powerhead. I'm getting more than 1 bubble per second. I don't have any clue what kind of rate that is... good/bad...


second post:

Ok, so in addition to my 65 planted tank, I have a 18 gal. rubbermaid tub that I have made a holding/growout tank out of... Basically I threw some substrate in it, and I planted a bunch of REALLY tiny pieces of plant that I had left over... as well as some of the crappier looking plants. I have been dosing it with excel and the flourish comprehensive... I have a 18w plant light on it that I borrowed to start a 2.5 gal. with ... well since I don't have a 2.5 gal yet, I was putting it to work on this thing. I also have a 24" double t12 florescent light on it.. the bulbs say UV on them, so I thought they may be good for plants. No aeration. No filtration. Nothing but plants, substrate, and snails. Snails were born in tank I guess... The plants in there are doing 100% better than the plants in my tank. I am mystified. Not a trace of algae. Plants are growing well. Pisses me off... hehe..


SO... now that I am doing the DIY c02, I have been sticking it in this thing at night. I leave the lights off in the day while the c02 is in the main tank, then turn them on at night and leave them on all night while the main tank is asleep. I just tested the water this morning... and te PH was between 6 and 6.5. I just stuck the c02 tube in there and put some filter fiber overtop.. no diffusion besides that... and the bubbles were rising to the top and popping at the surface.. As I said, PH was about 6.2... and KH was 3. Putting those measurements into the calculator from my link in the above post gets me nearly SIXTY EIGHT ppm of c02. Can that be right?! Is this why those plants are doing much better? Can you actually get THAT MUCH c02 with zero diffusion from DIY? It seems really weird to me. IS that calculator WRONG?

Hopefully someone will have some sort of answer.

HOw does everyone else measure the amount of c02?


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

My tank journals
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
&
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
non_compliance is offline  
Sponsored Links
Advertisement
 
post #2 of 5 (permalink) Old 01-14-2010, 04:56 PM
Are these real?
 
Wasserpest's Avatar
 
PTrader: (195/100%)
Join Date: Jun 2003
Location: Monterey, CA
Posts: 15,636
Good questions...

1) Chucks calc sheet is very accurate as long as you don't have things in your water that upset the balance. As soon as you get humic acids, an imbalance with the carbonate/bicarbonate ions, or anything else messing with pH and dkH the results will be off.

For example, if you use peat in your tank, or your water goes through some sort of water softener, the equations won't be valid anymore.

Another thing to remember is that your test kits might be off. Little variations in pH testing lead to rather large changes in your calculated CO2 result. Not an issue if you have some double-digit precision calibrated pH meter, but if you guess a pH between 7 and 7.6 via a color match (liquid or strip) it will make it hard to use.

1b) Your plants will always benefit from an elevated CO2 level, whether that is 10, 15, 20 or 30 ppm. The trick is to keep the balance. For a medium light tank, 15ppm will be great, as long as you add the other nutrients along with it. For a high light tank, it should be cranked up a bit more. Whether you really need to reach some magic 30 or 50ppm number that someone made up is something you need to figure out for yourself.

2) I think the calculator is right, but your measurements are wrong (or off a lot). For example, why do you get 3 dkH in your tab, and 4 in your tank? You say pH between 6 and 6.5... Etc, see under 1).

To prevent the issues with measuring CO2 people invented the drop checker, where you use a 4dkH solution made from distilled water and some indicator solution, and that will tell you more accurately your range of CO2.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Wasserpest is offline  
post #3 of 5 (permalink) Old 01-14-2010, 07:41 PM Thread Starter
Planted Tank Enthusiast
 
PTrader: (33/100%)
Join Date: Dec 2009
Location: Michigan
Posts: 632
Ok, I have read a bit on the drop checkers, but not a TON because I don't have one yet and wasn't sure if I would need one.

I noticed what you referred to... if you change the PH, it can vastly effect the outcome... I wasn't sure about the difference in KH either. Water is from the same source. I thought maybe something in the tank was buffering the KH a degree... not sure what that would be... maybe the rocks I have in the main tank, where as there is nothing but substrate in the Tub....

I have been taking the DIY CO2 cannister COMPLETELY OUT of the tank during non-photo time... is that bad for my stability?

So, either way, sounds like I"M accomplishing SOMETHING.... even if it's not super good, I"m headed in the right direction. THat makes me happy fwiw... Thanks for the tips.

I believe my tank is probably medium light... it's a 65L which is a 55 footprint, but a little deeper... so my light really has to penetrate a lot. I'm using a 260w power compact with 10000k lights for now.. I have another 56w 6700k light that I had on there, but someone told me that was way too much light for no c02... maybe I can get things more balanced out with what little CO2 I have...


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

My tank journals
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
&
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
non_compliance is offline  
 
post #4 of 5 (permalink) Old 01-14-2010, 09:15 PM
Are these real?
 
Wasserpest's Avatar
 
PTrader: (195/100%)
Join Date: Jun 2003
Location: Monterey, CA
Posts: 15,636
Sounds like high light to me. 260W? Half that for medium light. I wouldn't tackle it with DIY CO2.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Wasserpest is offline  
post #5 of 5 (permalink) Old 01-15-2010, 03:43 AM Thread Starter
Planted Tank Enthusiast
 
PTrader: (33/100%)
Join Date: Dec 2009
Location: Michigan
Posts: 632
hoppy was thinking that maybe it's lower than high... based on the depth of the tank, and the quallity of the fixture... who knows.. I've got a lot of trial and error to go before i get things dialed in... I am considering only running 2 of the 4 bulbs though...


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

My tank journals
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
&
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
non_compliance is offline  
Reply

Tags
None

Quick Reply
Message:
Options

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

Password:


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

Email Address:
OR

Log-in










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