[Hogwarts]

Agae won't hurt them. It'll prob give them some more vitamins. Since when have pigs only drunk the purest clearest water?  I've used tanks where the water goes green for years with no ill effect. However, if you do paint the entire tank black, it's easy to tell when the level's getting low as the water comes out a lot slower so that gives you some warning. But also you just feel the tank itself. on a hot day the water feels cooler than the empty tank above and on a cold day the water keeps its heat and feels warmer, so you can definitely tell where the water level is.

Maybe but an internet search says some algae can be bad even lethal for animals also I was worried there is the risk of the algae blocking up the nipple drinker attached to the container stopping the flow, also it just looks bloody horrible looking inside seeing the algae. Anyway its all painted now and seems to be doing the job the air inside does get bloody hot on a sunny day though , I'm thinking it might be better to take the lid off as I think I've got a greenhouse type effect going on there.