Hello i have been having issues with my bud being airy and loose. I have tried numerous strains and bought seeds from multiple vendors, the buds all usually come out around the same density. I have 4 viparspectra p1500 lights in a 5x5 tent with one plant under each light around 12 inches above them on a 18x6 light cycle. I have been using foxfarm ocean forest soil and start giving nutrients about a month into the life cycle. I follow the foxfarm recommend feeding schedule and use the big bloom, grow big and tiger bloom nutrients. I give them nutrients every other feeding and started using the foxfarm open sesame, beasty bloomz and cha ching nutrients on my latest plants.My temperature usually stays around 80F and humidity is usually around 50%. My plants do not show any obvious signs of issues, no browning yellowing or anything. Please let me know if you need any more information, any suggestions are appreciated. These have all been autoflower plants
All your buds or just the lower stuff?
600 watts is not a lot for a 5x5 and have you tried photos
The top of the plant will come out denser but i would still consider it loose
we have several photos outside. We dont utilize the whole tent the lights have been centered over a single plant since the start of their life
Autoflowers are naturally looser then photos MOST of the time. I think its a ruderallis trait. Think of it as the tradeoff between the two types. Auto’s looser and lighter but faster to harvest, photos denser and heavier but take 30 or more days longer then autos.
We can compare notes well as I also use FF trio and FF pk boosters with FFOF soil. Only cple things I do you may not. I also use FFSF in the bottom 1/3 of my pot. (Which I recommend trying) I add silica and this last grow used great white shark and unsulferd molasses. (Which I also recommend trying)
What kind of plant training are you doing? Lollipoping and selective defoliation can help make for denser buds, kinda slimming down the number of flowers the nutes go to gives better overall flowers. Kushman chiropractic can also increase thickness of branches which allows more nutrition to flow through the plant.
I used to do LST and would trim off lower bud sites that would most likely grow popcorn buds. As well as cutting off dying and large fan leaves. I have cut back the last couple grows on trimming and LST because i read it can stress the plant. I have not noticed much a difference in the plants.
Some stress is good. THC production can be increased because of well timed stresses. With autos you have to be choosy which ones you stress, gotta be healthy, and even then walk softly.
I recommend not cutting fan leaves due to size when it comes to auto’s. Instead train the leaves out of the way tuck em under forming tops if you have too. Autos need all the solar panels they can get.
Wow your growspace is huge! Im with a previous poster, you dont have alot of light for such a big space. Alot of a lights effectiveness can be found in matching it to your growspace. The photons bounce off the walls and get absorbed by the plants. In your setup, there is alot of space between everything photons getting lost to distance. Could explain some of your issue. With multiple lights like you have I would think you would get better results with tents to match flowering perameters of lights. Take my light for example fc3000 from Marshydro. It has a 3x3 veg footprint but a 2.5x 2.5 flower footprint. Put that light in a 4x4 and it isnt gonna do so hot.
Your flowers look pretty standard for autos, i guess.
This a flower I grew under a ts1000 in a 2.3x2.3. A perfect match for that light.
That looks very similar to what i get out of my plants. I have been growing for a year or so now and constantly compare my bud to what is available on the street and they are usually alot denser. I have not had any issues with potency so i am thankful for that. Ill look into training the plant more and adding more light. Appreciate your time and knowledge
I agree with @Docnraq ,@Budman121 I think your lights are too small for the space. Just upgraded my light for a 4x4 tent, got a guy making lights like the diablo lights. Havent installed yet. I had the exact same issue with my last grow, which is why I upgraded. Do some research, there are awesome lights out there for a reasonable price. Facebook marketplace is a great resource, just know what you should be paying before you jump in there!
What are your temps? I use a p1500 alongside a diable 200 and the p1500 shot my tent up almost 10°. The drivers get real hot when cranked up, and the board itself puts out a pretty good bit of heat.
Sorry just saw they stay around 80°. Is that at lights out as well? You may try 6/2 and that can help keep temps down. Or lights on during night time.
I am going to pull up my soapbox here for a minute…
Decades ago, when selling cars, dealers would joke about the white cars being on the lot the longest. Somewhere someone started the idea that white cars hold their value better than other colors. Logically thinking about that, there is no reason for a white car to have any tangible value that’s better than a red or blue car. By far the most common color cars I see with paint cancer are white, but the fact remains that by and large people still think white cars hold value better. And guess what, they do. And why do they hold value better? Because a significant number of people bought into the idea Enough that it has affected the entire car market. Dealers stock tons of white cars. I personally hate white cars…BUT… If I were a car dealer I would stock a lot of white because people think its true and have made it true because of believing it.
Now in my opinion, which I know is different than most but I am a freak, Dense Buds are nothing more than white cars. Its a quality of cannabis among many traits that somehow has been labeled and promoted as the “Best” thing to look for in the end product. I get the appeal…More weight in less space…But there is no more THC in there by weight than in the loosest autoflower buds. THC content can actually be better in the loose bud than in the dense ones. Personally, I don’t worry about it at all. It happens randomly and to different degrees among plants. Autos tend to be looser than photos but there are several other differences between the two types of plants as well. Now what if I was growing to sell the buds? I would absolutely want rock hard dense buds because people believe they are better. And If I wanted to sell a lot of weed I need to grow the most marketable product I can. But its all perception. A dense bud is just a different structure and not necessarily a better structure. The final product may be inferior in many ways to a good quality looser one. THC content, Terpene Profile, and the effects of using it are far more important. The two or three hours I get to enjoy the use and effects of the weed is much more important than the three seconds I get to squeeze it.
So then I will step off my soapbox and return to my hermit cave.
All the advice given is great and will help produce those dense buds. I currently have 4 plants in the tent. 2 are producing dense thick buds and 2 are producing lighter ones. All under the same lights and fed the same. Commercial growers choose a plant with that quality and clone it to sell to dispensaries.
Anyway…
Please don’t bash be too much. I know this is a hot topic and a passion for many growers. It rivals discussions of what Pizza is the best. Maybe I will start a thread on that… 
@Spiney_norman FTW! I agree, and there seems to be alot of new growers with just amazing plants down on that their buds arent “rock solid”. For me, as long as it tastes great and is high potency…I could care less about how hard I have to twist my grinder.
Yep. Once its ground up who can tell anyway.
It’s New York. End of discussion.
I do love it too. 
@Spiney_norman + @Docnraq , yes, yes! My question is always this; what is the first thing a person does to a “rock hard” bud after fondling and admiring the thing?? You break it up and make it airy to de-carb it…no? It’s the cannabinoid % that makes the difference. Dense bud could perhaps have less % than an airy, per weight. Yins have sound reasoning! What a concept.