General and carbon hardness: doubleyou tee eff?

[sudz]

Hey all, i biked to big al's and got the hardness tester, as i was curious, and i'm gathering its almost a necessity if i'm to continue using my DIY CO2 system (But i could be totally wrong)

Anyway, can anyone tell me what this MEANS? the instructions don't give me anything but PPM or degrees.

*lost look on face*

The PH tested at was 6.8 (tested before hardness)

Carbonate Hardness (KH) read as 3.5 degrees, or around 60 ppm
General Hardness (GH) read as .5 degree, or 9ppm

If i read these instructions right, my KH is decent for a planted tank but my GH is too low? Its just a generic chart thing, and it says: GH and KH levels. Doesn't say anything about them not being the same :-S

Also, if it matters, i did a 15% water change 2 days ago, AND replaced the polyester in my filter at the same time.

I've recently added new plants, removed my bubbler, and JUST today, picked up a regular socket 10 watt PC screw in light (6700k), though that shouldn't have had any effect in the short 45 minutes its been on.

Do i need to do anything? hows my tank doing? Nitrates, Nitrites, and ammonia are all at the bottom of the scale.

Temp is steady at 80*F

If i need anything else... please tell me!

Thanks a million

 

[rich311k]

Yoor CO2 is about 17 ppm. So you are getting there. See how it test tomorrow. Your numbers look good. What were your exact readings? and did you get a phosphate test. Are your test liquid tests?

 

[cplawrence]

The main idea behind the KH part of this is that there is a relationship between the KH, pH, and the amount of CO2 in the water. Check out http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm for a nice calculator. For example, with the numbers that you posted, you would have about 16 ppm CO2, which is pretty good. As far as I know, the GH is less important but it is an indication of the mineral content of your water, some of which are important to plant growth. If it is too low, you may find yourself needing to supplement.

 

[sudz]

ahhhh... ok. This now makes sense. Thanks rich and lawrence!

Its a liquid test. Basically add one drop and stir. I keep adding one drop at a time until the solution changes color. It mesures in degrees (one degree a drop)
I get my ".5 degree's when it doesn't TOTALLY change color (kinda murks between)

I'll read those links when i come back from london tommorow night. Is 16ppm good? what is PERFECT?/damn near close?

Thanks again!

 

[sudz]

Oh. THe guy at Big al's was saying that it couldn't be done, testing your CO2 with a PH and Hardness test. he said i HAD to buy the 32 dollar CO2 tests (only 5 tests per box!!!)

*ahem* RIPOFF *ahem*

 

[rich311k]

He is wrong.

 

[TomK2]

Think of KH as "carbonate." It is measuring the carbonate hardness, which co2 is in equilibrium with, and pH is affected by. Thus, to calculate co2 you need to know the pH and the KH. General hardness is the other minerals, such as postively charged metals like calcium, magnesium. KH buffers your tanks pH, GH usually does not.

 

[BrianNY]

Exactly right TomK2. I have the feeling that Chuck Gadds calculator is rather loose for determining CO2 content. Probably more of a guide than an accurate reading.

The amount of CO2 you want in your tanks sudz, is approximately 25ppm. If the CO2 gets too high your fish will suffocate so it's important to keep an eye on it. Although CO2 is great for low light tanks, it becomes even more important the more light you have. Lighting is the engine that drives photosynthesis and allows the plants to utilize the CO2 you are adding.

 

[sudz]

Lighting is the engine that drives photosynthesis and allows the plants to utilize the CO2 you are adding.

AHHH... this is why it pops up to 23ppm during the night, and 18 during the day...

Only a PH difference of .1 From 6.7 at night to 6.8 The fish can handle that ok, right?

Yeah, My GH is almost non-existant, will that have any repercussions?

Thanks again everyone for putting it simple! YOu said what other 3 page documents said in a few sentences!

 

[workfortheman]

sudz, out of curiosity, what method do you use for pH testing? Do you have an electronic tester, or the color charts?

 

[sudz]

Color charts by a white florescent light. I measure 5 ml with a sterilized syringe. I used to use my pool tester for the first bit (when i first got my tank)

The chart goes in .2 intervals, however, if the color is inbetween two card colors, i just call it .1

should be accurate, right? I'm pretty sure i take more care then most when testing all my tank... Its just i have a fairly cheap tester. (35 bucks for a Nitrite, Nitrate, Ammonia, PH and High PH test. and 8.99 for the GH KH tester.)

 

[sudz]

Color charts. and a florescent light. If its inbetween colors, i made it a .1 instead of .2 (what my PH tester's are)
Its spot on when i checked to see if it was the same as my pool PH tester.

 

[BrianNY]

You're good to go. The low GH is fine. It's the KH that adds stability to your pH.
Put some pics up when you can sudz. We love planted tank pics.

 

[malkore]

the CO2 chart is off by no more than 10%. I've seen the math to prove it.

so in the ranges we seek, you can't be off by more than 3ppm. not super precise, but a good enough guideline.

Remember, we're not building rocketships...we're growing aquatic weeds.

 

[sudz]

You're good to go. The low GH is fine. It's the KH that adds stability to your pH.
Put some pics up when you can sudz. We love planted tank pics.

I do have a few up in my gallery, check em out! i'll be taking more pictures tonight, with luck with my dad's camera, its got a MUCH better macro