I have previously tried to get on the Internet test descriptions for this article, but they were, to put it mildly, rather mixed. Some wrote, the 'sponge' would scratch the discs (which was added at the same time that this happened in the base area, when had sneaked pebbles between Blanki and disc). Others thought the description was misleading because calcium deposits would therefore not get a grip. I say it this way: If I, there are stones between any cleaner, and it was a cashmere scarf, and the disc will bring scratches. This is what happens even when Blanki pad. Otherwise, this part is the solution to all my discs-pollution problems. I have since about 10 years tanks in use, and just when one performs a disk cleaning regularly, very stubborn deposits are green from inside the windscreen. The one can get relatively good with a razor blade scraper with the handle when the disc is just. But I also have a jewel-aquarium with a convex panorama windshield, when these devices inevitably lead to scratches, because the outer edges of the blades just exert a higher pressure on the disc. I've tried everything: insect sponges for cars, hard sponges for pots, special floor cleaning sponges for tiles. The green pests just did not go away. The best was still working a decommissioned Cheque Card. But you have to exert a very strong pressure, what's going on muscles and intervertebral discs and lasts forever. This Blanki pad on an extremely robust, about 45 cm long aluminum bar you get in the first stage 80% of the dirt away. Which reminds me of the bar was perhaps a little too short, because my tank is very deep. In the second step to me the rather short bar but came back to good, because I have not taken off the pad (which is quite, but fiddly) but simply touched the pad down and exercised with the still attached rod direct pressure on the disc have , So clean my jewel aquarium was not the last 3 years. It's quick, it's easy and simple, just great. Calcium deposits are indeed mostly outside of the water level, there is one with the Blanki loud operation Description not arbieten. But the edges of the water table it works well, even against lime. In the water sector really are no scratches observed. The steel wool pad is very thick, I now do not know why you should wear it quickly. Looks like it would last forever. Nevertheless, I have a pack of refill pads ordered, fairly priced. Am absolutely satisfied and did not think that there is a solution to this eternal vergrünten discs. But is there: Blanki! Addendum: As I said, I had 'Refill Pads' order, who came only today. Unfortunately, I realized that since only one pad in it. And that costs 7.20, so a full 20 cents less than the set with the cleaning rod. Would therefore always order with the bar which is so sure sometimes broken.