Newly Bought (10) Selection African Cichlids - One Appears 'not Normal'

So ppl, that wuz Tuesday - rinsed the gravel, was just enough to cover the footprint.. then dosed it wi' dbl dose of the Tropical Pearls to seed the filter - oh - and about 50% of the water was from water change in the cichi tank and the 90L - me thinkin' that it'll prolly have 'minimal' ammonia and nitrites to help seed the filter, but some nitrates hafta fix later wi' water changes.. meanwhile I studied the 'no-fish and 'in-fish' cycle posts in this forum - but really had no choice but to attempt the 'in-fish' method..   after 24 hours the chemos in  the new tank were virtually same as the 90L - nearly zero ammonia, zero nitrite, but close to 40 on nitrates.. so, second (single) dose o Pearls, and moved 5 of the largest fish from the 90 to the 250, that was 2 x 3-inch Angels, 2 x 3-inch Clown Loach, and one 5-inch Siamese algae eater .. their combined 'volume' prolly account for half the ammonia load in the 90L     .. tho' there's still 20 smaller species still there .. ok, they 'survived the first 24 hours, seem to be a bit lonely, but plan is to transfer a few more later.. we now into 2nd day of the transfer, and following water change in both tanks ( earlier today, Friday ) the chemos are slightly better in the 250L than the 90L, where nitrate is still hovering around 40ppm.. third day of dosing the 250 with the Pearls tomorra.. really impressed wi' how fast it kick-starts the cycle.. with the much bigger tank, and bigger filter capacity, I'm hoping I won't get much in the way of ammonia / nitrite spikes.. so, looks like 'the move' has prevented the 90L situation gettin' worse.. and we added live plants to both tanks as well.. I also took the 2nd Fluval U3 filter from  cichi tank and doubled up wi' existin' U2 .. but not impressed wi' the 'bio filter' aspect of this filter - seems like Fluval put more emphasis on the carbon, which to me is wrong way round.. So, bottom line, is there anything else I cud, or shud have done ? - from now on looks like close monitoring, and water changes to reduce nitrates - I want to try to avoid adding 'quick-fix' chemicals, for nitrates or anything - rather achieve the balance so the filter(s) are doing the work..

Thks Sue.. So, mebbe  panic over - 60% water change in the 90L, zero ammonia and nitrite, and nitrate back under 30ppm.. no spikes in the 250L so hoping to gradually fill with more of the 90L fish over the next few weeks.  This post seems to have slid away from my original cichlid problem, and become 'filtration issues'.. but the cichis and 'stripeyJoe' all look good, and good tank parameters, so hopefully no need of further posts there.
         I'm still concerned about the bullied Strawberry - only choice seemed to be 'dispose' or transfer.. she appears to be swimming OK, but not eating.. so, to give her a chance, transferred to the 90L 'community' tank.. even there she seems shy - currently 'hiding' behind a U3 filter as she used to in the other tank - the other fish appear to have 'accepted' her.. I'm hoping she hasn't got some disease passable to the others - it's as if she's had a 'personality change' ( from a 'normal' cichlid ).. or perhaps she was a 'bullied female' - more 'watch and wait I guess...haven't got a quarantine tank available yet - bit late now anyway..