I was bit sceptic about paper water tester but I had a chance to compare with my master kit (liquid) and the results seems to be very accurate. Well worth money and it takes sec to check the water rather than 10-15min using master kit.
The Tetra test strips were simplicity itself. A neat little tube of 25 strips with clear instructions and suggestions on the chart of which values would mean I need to change the water in my tank. The separate ammonia test strip set was just as simple and easy to use – a vast improvement on waiting 5, 10 or 20 minutes for colours to develop having faffed around with drops of fluid from several bottles. I tested these strips against the dropper bottles and the results were confluent. The Tetra version were smaller with a container that was much easier to open, which was nice.
My daughter uses these by herself to look after her first tropical tank. She had been really struggling to test the water and needed lots of help. Now it is so quick and easy a child really can do it! She is looking after the fish herself and even better it doesn't seem to end up with half a gallon of water on the floor!
I ordered the dual pack. I now test my water much more regularly and am sure my fish are happier that I'm keeping a better eye on them. The chart and instructions are easy to understand making the whole process quick and painless (for me and the fish ;) ).