This is a subject close to my heart because I went on holiday for 14 days and when I got back my tanks were decimated.
My friend had had problems with the lights, which I'd asked her to turn off if the tanks got too hot, because she couldn't get them back on again afterwards. So my lights were out for 10-11 days and when I got back, all my plants were dying.
This sent my nitrate levels through the ceiling, causing terrific over-growth of brown algae. The temperatures in my tanks continued to rise to 90F on some days and to cap it all, my friend misunderstood my instructions and over-fed all my fish!
So, having learned from this terrible experience, I've realised never to trust neighbours to feed the right amount. I had explained to my friend about over-feeding, about how fish were cold blooded so didn't need as many calories as warm-blooded, etc etc. But my mollies are cute and greedy, and my neighbour is soft-hearted.
I don't know much about discus, except that they're expensive and won't eat flake, but I presume they can go several days without food, like most fish? If so, why not get a neighbour to go in
once during your 8 day vacation and feed your fish a pre-pared, small amount of food?
The two biggest dangers to your fish are over-feeding and temperature. Discus can probably cope with high temperatures and anyway, the heatwave seems to have past. Oh, and then there's power outages, but that's a problem if you're there or not - give your neighbour a battery powered pump and ask him to set it up should the worst happen.
Good luck!
)
