Just seen link opps!
63l (16gallons I think) 60cm, 30cm, 35cm
fish 3 Cherry Barbs
tank 1 month old
had a rise in ammonia levels between 0-0.25 a week after getting fish
ammonia level 0 now, nitrite 0, ph 7, nitrate 5-10
using liquid API Test
water temp 24-25c
no live plants yet, plastics plants only, having enough to cope with looking after the fish at the mo but will be getting real plants soon.
did water changes every other day for a week to get rid of ammonia.
once a week at start and now 20%
light on 8-10 hours day tank out of direct sunlight but in well lit room
not sure of filter make, got fluval tank which came with filter, heater, light in hood.
I'm asking if the silver spot means fish is sick cos I was planning on getting more fish and I didn't want to put them into tank if there were problems. But I've already got the next fish now since I've come up with nothing on net and thought it might just be a marking, put them in the tank yesterday 6 cardinals (I know not beginners fish or very hardy but I did send my partner to get 2 dwarf gouramis :D )
Well hope this info's helpful and I'm hoping my cherry's not sick.