Hi, Been having a problem with my drop checker wherby it dislodges from the glass and empties the contents into the tank. Is the bromothymol blue harmfull to fish or fauna and if so in what sort of quantities? This has happened twice since yesterdays tank maintenance. As I use 4 drops in my DC, 8 drops have been put into my tank water (250Litre) in the last 24 hours. Should this be any cause for concern? Also does anyone know where I can get replacement rubber suckers for the JBL permanant co2 test set? Regards, Chris.