Not to be a d*ck, but how often is this question asked? i think the mod's need to reorganize the forum layout so there's a giant SEARCH button on there so when this question gets asked the 8 million previous identical posts of the same responses come up. Even if we knew strain, environment, light intensity, nutes, TDS reading of the water, temps, height, etc. it would still be a ball park estimate of how much you'd get. If you dont do one thing right it could drastically reduce yields, like over watering/feeding. READ, READ, READ.... best advice you can get on here, before you just post a question, smoke a bowl, sit down, relax, and read every post you can til your eyes hurt. EVERY question you could possibly think of has been asked and probably answered already on here, so just do some searching, it won't hurt you. goodluck with the grow! and dont take it to heart, people on here are hard headed and usually dont listen so we have to reinforce the point on here!