yield getting worse

We'll thanks to all in advance. I've been growing indoor for about seven years now but in soil. A buddy hooked me on to hydro recently and I love it but to make.a.long story short my yield per plant is getting smaller and smaller I used to get 2z a plant now only .5 on some 1 on others. My grow is a 4x8 tent with a 1000hps and a 1000 mh. Im using bionticare nutes ppm is 800-1100 depending on stage of flower. I've been using Ph 5.6-6.2. Lights are air cooled and a little less then a foot above the canopy. Buckets are getting a ton of air. I know it is not genetics I've been switching strains up and I gave my friend a clone and he got 3. he has a small closet with a 600 hps. my tops buds are nice but that's it the rest is so airy it may as we'll go to hash. The only thing he did different was smaller room and less plants and flowered shorter. So I've been flowering at 12-16 inches but same result. Sorry to go on and on but this is pissing me off. I've grown better plants with a 400 watter like I said my Main Cola is good but the rest sucks. Any help would be awesome as far as spacing goes I have 18 plants in the 4x8 the only thing I can think of is not enough light or new bulb or co2 but 2000 Watts a foot above plants seems like plenty when he's using a 600 and.the bottom buds are as good as my tops. Thanks again in advance. I just need help to figure why every grow is yielding less per plant. Bulbs are a year old. 12/12 every day

I would honestly put money on your bulbs, go buy two new hortilux eye bulbs and i would say that your yeild will for sure increase. I just had this same problem and just by replacing my shitty chinese bulb with a new hortilux eye, my yeild almost doubled(for real)

You might be cooling the lights too much, hps bulbs produce more lumens when they're hotter so maybe reduce the airflow across them. I would definitely change the bulb as well if they're a year old... I haven't met anyone that has been able to match my yields with open bulbs and I'm in soil!

Watch this video (I don't care for the Gavita's but there is other information that pertains to what I mentioned.)

http://www.youtube.com/watch?v=n9nTtIHrUss

I agree. You should be changing your bulbs every 2nd or 3rd grow to keep a consistent yield and happy ladies.

If your yield has dropped may I suggest going back to doing what you were doing.

All right guys a new bulb it is. I would go back to what I was doing soil but I like hydro so much better now. No messy dirt to bring in and out. Water I can just drain. Thanks for the replies. I hope it's the bulbs if not I have no clue

Sorry for the glib bluntness of my post. I respect your commitment to hydro, you are bound to improve. Hope it goes well dude.

Worth trying some low stress training in veg too. That is what really helped me. Tie down the top to one side of the pot in veg, you really need to get it lower than the rest of the plant. This way you created multiple tops without topping. Leaves you with an even canopy, leading to more colas and less popcorn. Well worth trying and far easier than I anticipated.