Anything over 800 is a waste and potentially harmful. Unless you’re running C02 in a sealed environment.Thanks man! How low would you take them? I've got them at 16", but I'm only at 75% and getting 1050 PPFD! If I've got room to turn them up how high should I be looking to go do you think in terms of ppfd/DLI? They certainly don't look like they're being pushed too hard and expressing deficiencies so I'm assuming they can take some more?