[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [APD] CO2 purity

I said:
>>Food grade means it needs to be tested for us to consume, there might be a tiny% of other, >>but non harmless gases mixed in. But would this be significant?
>> Nope.

Jerry said:

>Umm, I think you missed the point. 
No, __look up__ how pure the CO2 food grade gas is(see below, I did a little for you). I've discussed issues like this a decade ago. You go off with out first doing any background checks suggesting 200$ a bottle pure gas. See below. I am trying to help you and save you from a bunch of work and added expense.
>The point is to test whether pure CO2 
>will dissolve before it can fly around the tank and collect on plant 
>leaves. You can't test that without pure CO2.
You most certainly can. Simply have the gas tested. Ask the seller/supplier, do some background checks with this same question. If less than 0.05% are impurities and the bubbles size does not decline/decrease significantly, then what else is in the bubble?
I know the purity of the gas I use. I know John who owns the place and asked. Others have investigated it out of curiosity over the years. Look it up on the APD and other forum archives. 
It's really not that tough!!!
See here:
About 99.97% pure.
Yours is 99.999% pure.
So you mean to tell me that the difference of 0.03% vs 0.001% and you can see this as being an issue with respect to CO2 for plants and bubble size/depletion?
Good luck.
And especially considering in the context of food grade vs lab grade when comparing each to 30ppm in water vs the pure/food grade gas. Show that 0.03% vs 0.001% impurity will cause significant bubble size and CO2 content differences.
The same arguement also exist for more precise ag grade chemicals and use research grade KNO3 etc.
I'd be careful not to get lost in the details and too much percision unless it's absolutely required and ask yourself is it really required to answer the question.
Why add another sig fig for 10X more cost and effort?
Does it help?
Our test kits, meters cannot possibly even measure such purities differences in CO2 levels.
There are ways to measure this, but not as a hobbyist. Even then, I'd not expect to find a significant difference in terms of dissolving rates. Does such precision make or break a method and routine for keeping weeds? How much precision do you need to see if it's significant?
>You have a singular focus on insisting nothing is necessary except for 
>your way ... even before you are sure what the purpose is.
It's not hard to predict the "purpose" with CO2 purity and bubble sizes etc and that is what this was originally about. Some background reading will help you and you will find it's not "my way", it's supported by many other folks, test and background research as well as a lot of experience. 
So we've gone a round with light, now CO2, so are nutrients next?
Tom Barr

Yahoo! for Good
 Click here to donate to the Hurricane Katrina relief effort. 
Aquatic-Plants mailing list
Aquatic-Plants at actwin_com