Bristlenose pleco

[hanziie]

Can someone tell me if my pleco is supposed to change colour or if hes ill please hes been like this since yesterday. On saturday i changed the filter in my aquael fan filter 3 and i checked all the levels in the tank yesterday because he had gone a lighter colour i noticed the ph was high and the hardness was high i checked today and the hardness and ph have gone down is there anything else i need to do
Thanks

 

[Barliman]

Is he refusing to eat?

 

[hanziie]

No after the tablets dissolved he went back and ate some i checked him once i got home today and he was black again

 

[Barliman]

That's good. He was probably feeling a little stressed, and the food improved his mood.