My Reference liquid arrived this week and I finally got the Drop Checker set up today. I added enough 4° KH water to fill the Drop Checker and added 3 drops of AP's PH solutiuon to this. The water started out dark blue and has only changed to light blue after five hours.

I would have expected to see a greenish colour by now. Assuming this is correct and my PH solution is not too old. WTH is all the CO2 going, it's always ON! A potential new problem.

First, the obvious: do you have any trouble telling green from blue? Some people have a semi-color blindness that makes that difficult for them.

Next, the blue color shouldn't change to a lighter blue unless tank water is leaking into the drop checker.

Assuming neither of those things is wrong, you just don't have nearly the amount of CO2 in the water that you thought you had. That was my situation when I started using my drop checker.

Further to what Hoppy said, you probably dont need that much water in it, i put enough to be able to tell what colour it is and no more, this massivly speeds up the response times.

Two questions...

One - Which type of drop checker do you have? I have both the ADA style (bulb on a cone) and the "teardrop" style. The teardrop style looks better to me, but I've found that with the teardrop checker the limited interface between the air in the dropper and the tank liquid lead to a much longer response time compared to the ADA style.

Two - Where do you have the drop checker located? I once put my checker in an upper corner that I think is a little more stagnant than the rest of the tank. The response time was pretty slow until I moved it to a better mixed area of the tank.

I have trouble with some colours of Green looking Red/Brown, but never a problem with Blue/Green. But I asked the Peanut Gallery to confirm and I was told it was a darkish Green, WTF? After consulting the colour chart we agreed on 6.8, same as the PH meter. So my CO2 s/b somewhere around 19, quite a bit less than I thought.

I'll have to try two drops (or less) of PH solution for the next batch I make.

I have the Tear Drop located about mid tank. But it's REAL hard to judge the colour with the Swords in the background.

Be prepared for a longer response then, but you should end up at the same place.

I've found that looking at it from the side helps so I've got mine towards the front half of the tank. If there's anything green near it its tough to judge the color so try to get a look at it from an angle with nothing green behind it.

Please help to find website that sales Reference liquid and Drop Checker .

for which country Misha? And do you mean the blue bromide? or the 4kh water?

Youll find most things on ebay, certainly the drop checkers and the reagent solution.

I bought my Drop Checker on eBay. It came from Hong Kong and took about 10 days.

The reference liquid I bought from Bill in the Trades & Swaps forum.

I just used some AP PH indicator for my measurement liquid.