orange ryukin turning black

Question
we have an orange ryukin that is turning black his fins are going black, just under his mouth and on the sides of his body are what looks like dirty smudges.  he does not look ill his personallity hasnt changed and we are fairly positive it is not fin rot.  the tank is 150litres the water has all been tested and scored 95% in a local pet shop.  we have moors, orandas,panda butterfly and ryukin 8 all togehter.  we cant seem to find out anything about this.  the tank has been up and running for 3 months.

Answer
Hi Louise;

The black is damaged tissue caused by ammonia and/or nitrite burns from "New Tank Syndrome" in the first 6 to 8 weeks after you set up your tank. When the tank was going through that period it burned the fish. The black shows up a while after exposure to the toxins but will fade as new tissue grows in. Not all fish experience this "scabbing" even when in the same tank at the same time. It just depends on how strong the particular fish is I guess.

He should turn all orange again, but it may not be as bright as before in those areas for awhile. Keep up with regular 25% water changes every week so they all stay healthy. It will also help avoid infection of the damaged areas that are healing.

Followups welcome

At Your Service;
Chris Robbins

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