Actually , it is the liquid. I just did the test (I only got the ammonia test kit because, as I said, I know our nitrate levels are high, have tested before and nitrate is always high, but I can't do much about it....and as has been said before here, I don't want to go messing with the water too much especially since it's been acceptable, apparently, for our fish, for the past several years. SOOOO... I was surprised that the ammonia level is between 0 and 0.25. It's yellow with just a slight greenish tinge. So apparently, it isn't the ammonia level that was the problem, although it could have been lower. The pet shop guy recommended putting a live lucky bamboo in the tank to control ammonia and nitrates. Is this a good idea? He says the goldfish won't eat it.