Co2 Drop Checker

[ricardo48]

Hi Everyone.


For my drop checker I boiled some tap water in a kettle a few times and then tested it for KH.

My normal tap water comes out at 14KH so is fairly hard.

After boiling several times I got it down to a KH of 4 when I used my test kit on it.

I have added this to my Drop checker which after an hour or so went a nice yellow/green colour to indicate sufficient Co2 ( about 20-30ppm)


However my drop checker seems to always stay this colour day and night and I am only use a Diy co2 system with no air stone at night.

Previously I used aquarium water in my checker which is KH14 but the solution never changed from a blue colour day or night.


Is using the boiled water ok? I am not getting false readings for whatever reason? As long as any water solution is a KH of 4 it will work in a drop checker?


Any help greatly appreciated.


Thanks

 

[neilanh]

Drop checkers aren't instant when it comes to adjustments. Since you're using DIY CO2 and no airstone, I suspect that your CO2 level probably isn't changing much at night anyway, so you're probably just fine.

In the future I'd recommend getting a lab grade kH standard. It's cheap and will save you the trouble of boiling your water down. It's much more stable too.

 

[ricardo48]

Ok thanks... so using boiled water is not invalidating my drop checker in anyway? What if the PH of the water in the DC is already below 7?

The drop checker needs a PH of 6.8 to go yellow on my chart, so can it be yellow because of the PH being low enough to turn the colour yellow already or is it definetly the co2 making it turn yellow?

 

[rkilling1]

Just a few comments:

My normal tap water comes out at 14KH so is fairly hard.

Hardness is dictated by the GH not the KH. KH indicates the amount of buffering in your water column.

Is using the boiled water ok? I am not getting false readings for whatever reason? As long as any water solution is a KH of 4 it will work in a drop checker?

Boiling water is just fine as long as you are going to drink it after it cools down. Using it for a drop checker, no way. You are relying on a test kit for the KH to be correct. Hobbiest grade test kits are far to error prone to give you an accurate reading.

Besides, what else is in your tap water that can effect the KH or pH reading? On top of that, the only thing you are doing is concentrating the solids/buffers/etc.. in the water.

I can see someone buffering RO/DI water, but you are still relying on a hobbist type of test kit for the KH to be correct.

 

[ricardo48]

Still the test kit says 4dKH so it most be there or thereabouts?

Cant be that far off the mark? Maybe a couple degree out either side but it is still roughly 4dkh solution?

 

[rkilling1]

Still the test kit says 4dKH so it most be there or thereabouts?

Cant be that far off the mark? Maybe a couple degree out either side but it is still roughly 4dkh solution?

LOL. A couple of degrees out either side? That gives you a band of 2 to 6 dKH. That's a very large band.

As an example we are going to say that your drop checker solution has a pH of 6.6. So what is the CO2 at a pH of 6.6? With a KH band of 2 to 6, the CO2 will be anywhere from 15 to 45 PPM.

A band of 30 ppm CO2 is not an ideal band.

 

[krap101]

If you have access to a accurate scale (maybe .01 grams) the best way is to get some baking soda and some distilled water. (I used my chemistry teacher's) and use this calculator. I made around a liter of dkh solution, and it was pretty easy.
drop checker for target CO2 calculator

heres some good links

Drop Checkers/CO2 Indicators-Why and How - Aquarium Plants - Barr Report

http://www.aquariumadvice.com/forum...-kh-solution-for-co2-measurement-88293-4.html

 

[ricardo48]

All seems a little complicated and alot of effort.

Fact is I know im using a reliable diffusion method my DC is green so I am happy for now.

Plant growth is good and the plants are pearling.