You’ll void the warranty if you use chemicals.
they are glass - what, tfr or any glass cleaner is going to ruin them yes they are so delicate I wouldn't use them outside where the weather might damage themDarran
I get on well with a local installer - they say unless its acid you can't damage them - they even got some out and drove their 4x4 over them - not even a scratch.some of these 'manufacturer' warranties are just their to stop people claiming against them for faulty products - as said we use tfr no probs - even pressure washed a 1000+ array with no ill effectsbest advice - if your not sure you can/want to clean them DONTI totally agree with what you have said ime just telling you what the manufacturer said to us and what is contained in the contract , that we had to sign when doing work for them , I did raise these issues with them and they said only pure water to be used end off Darran