Hi all
a few days ago i got my new drop checker from a guy off Ebay .and i just want to make sure i have it working right .ok this is what i did .i could not get hold of any distilled water for love nor money . in the end i got some De-ionised water from a car shop .for £1.99 a Litre. i then found i could get a Litre bottle from wilkinsons for 54p . just my luck .Anyway i mixed some bicarbonate of soda in with the de-ionised water till i got a reading of 4 degrees KH water . i checked this with my KH test kit . i then added 3 drops from my PH kit till it went a dark blue color . heres some pics of how it looks going through its color change .do you guys think this looks ok .

the first pic is just after it was put in the tank . the next one is it starting to go from blue to green after about 2 hours . the last one is after 3 hours

That looks just right to me. Congratulations! You now can be sure you have adequate CO2 in your tank.

Nice! its a nice feeling finally knowing exactly whats going on in the tank. Oh and de-ionised water is the same as distilled anyways.

Thanks guys ,its nice to know im doing something right .i have been reading on another forum that some people are baking the bicarbonate of soda and mixing it with 5 Litres of water .is this something i should be looking in to

I think the UK's Aquaessentials is carrying the pre mixed referenced KH solution for a few$.

Might be easier.

You figure 6mls every 2 weeks of KH ref solution abnd 500mls will go a long way, a little over 3 years and will be about 100-1000X more accurate. Note, even the baking soda method is still about 5-10x better than a KH test kit.

You can also double the amount, or triple it, when using the KH test kit BTW.

So if the test says to add 5mls and each drop = 1 KH unit(17.86ppm), then 10mls will yield each drop 1/2 KH unit (or 8.93ppm).

The accuracy of the Ref solution will be about 0.01-0.001ppm or so.

So then the only area of measure that's less accurate is the pH measurement.

And that's up to your eyeballs and color perception, or you can switch over to the
pH meters.

Regards,
Tom Barr

Thanks Tom .i just sent a email to Richard over at Aquaessentials and he tells me that they will be selling the pre mixed referenced KH solution soon .in about 10 days time . so i think i will wait for that . as this will work out cheaper than mixing my own .

Hi
I think i have a problem with my Drop checker . my lights and co2 are on for 10 hours a day and there off for 14 hours a day .but today i was looking at my drop checker just before the lights come on and it was still green and there had not been any co2 put in the tank for 14 hours .how can this be ? anyway i took the drop checker out of the tank and after about 2 hours it turned blue ( no co2 ) so this would mean that my tank is keeping 30ppm of co2 in it for 14 hours . how can that be right ?

Might want to change out the solution inside the drop checker, also, place it where some current flows past it.

Regards,
Tom Barr

Thanks Tom .well i can rule out one of them .i have it near a flow so it cant be that .so i will change out the solution and see how that works out

By the way what chemical is used as pH indicator in these drop checkers?