T/U :Littlefish for your helpful comments - quick update - the fish survived the night, but little change in appearance, colour or action - still 'panting'.. others quite lively and feeding well. So, other parameters - the tank: I will admit, I was in a hurry to get it up and running, but with some justification - here goes - we already had a 90L tank currently housing a common plec, and two 'gifted' fish.. one a Tanganyika 'Frontosa', the other a South America 'Red Parrot'.. and not knowing anything about these species we were unaware that they were incompatible. However, they were 'housed' for about the last 3 years and grown from 6cm to about 14cm - ( so the Frontosa now about 1/2 full adult size). My recent 'research' revealed that we should separate these two fish, and not house the red parrot with any planned Malawi cichlids. I found a tremendous 'deal' on gumtree - a 450L tank with stand, with ( very expensive ) Fluval FX6 filter, heater, gavel, test kits - the lot - and some 30+ tropicals of many species 'passive' community fish.. ( my estimate well over £1,000 for less than 1/3 that price ).. it was reasonably 'local' too and seller delivered it to me last week - I had it filled, de-chlorinated with 'Tetrasafe', and filter up and running within 8 hours - the sellers' fish were transferred to my 90L tank, while my two large cichlids were in a bowl.. a quick ph and ammonia test indicated the new tank was OK and had no choice but to transfer the two cichlids.. they survived the weekend, with parrot chasing as usual, so on Monday I delivered the parrot to my local aqua shop, and chose the 10 malawis as mentioned - kept the Frontosa who appears 'much happier' not having to hide all the time.. I'm sure 'other bio' parameters are good in the new tank, as it was a working set-up with fish only hours before I took delivery.. there ya go..