I was about to write for advise because my GBR always have dull colours. So I first tested my tank water: Nitrate 110, nitrite 0,3, ammonia 0, Ph 6.0. Nitrate was to high, so I did a water change. The day after I noticed a strange white spot on one eye of one of the GBR. The day after, so second day (today), the white spot was biger and the second GBR started to also have a white spot and I notice that the eyes with the white spot were bigger. And the fish with the bigger white spot is turning dark grey. Now the nitrate is at 10. What should I do please? 20 g 2 german blue ram 2 gouramis 1 corry 2 glowlight tetra 5 black neon tetra 6 rummynose tetra Here you'll have a bigger image if you click on the picture.