Hi all, i'm 5 weeks into my 5th grow (cheese, 400w sodium on light rail, room length 8' depth 3' height 6'). 3 of my clones died so i have 5 in the tank; i originally cut 8 squares for my 3" rockwall cubes. I've done 8 grape and rhino in the past but yield was dissapointing, so i am wondering with correct spacing what is the best amount of plants to put in?

I'm looking to buy a new sheet of corex card and a friend reckons i'd get better yields with only 2 plants but i cant bring myself to only put 2 in such a large tank!

i've got 8 rhino clones just rooting into rockwool cubes for grow no 6, but i fear i may just be overdoing it in the belief that more plants mean more yield.

I know it can depend on the strain, but a general rule of thumb from you all would be most appreciated. 2,4,6,or 8?

Hi pilgrim, would all depend on how long you veg / train your couple of plants. You could make two huge monsters if you wanted to versus 8 small plants vegged for half the time. The choice is all yours. Two huge plants could produce more than 8 smaller ones, again all depends on how much room you got etc!

Love the avatar mate.....sacre bleu, quarter pounder

Healthy cannabis plants grow on the basis of a Christmas tree with the base of the plant being as wide as it is tall in most cases. If your yield was disappointing consider the following potential fixes:

#1 - Big root masses make for big buds. If you have underdeveloped roots, your plants will "dwarf out" and yield will be disappointing. The solution is to add SM-90 to your reservoir EVERY time you change nutes.

#2 - Got gunk? Algae blooms consume food, roots and oxygen in the solution like it was a video game. Keep your tank spotless and change out your feed lines before crud builds up. Every tank change clean the tank connections, pumps and powerheads in hot soapy water to which a generous measure of bleach is added. This keeps the algae beast under control and prevents grow disappointments.

#3 - Is there enough oxygen to the roots? Is your nutrient mixture sufficiently oxygenated to keep the plants happy? I put a powerhead in my reservoir for the sole purpose of putting more oxygen into the tank. You can get the same effect, more or less, by using an air pump and one of those pimped out airstones.

#4 - Were there deficiencies in the nutrients? I use the Lucas Formula so I never have this problem, even though I see slight magnesium deficiencies which I deal with by using CalMag+. This leads to the question of nute lock-out. If you are using additives, they go in the tank last because they can cause lock-out. if you are having lock-out consider a new nutrients program.

#5 - Patience isn't a virtue, it's a requirement. Are the plants going long enough in flower? Early harvesting is almost a guarantee to disappointments.

Stick with it. You can get there from here.

some good points above^^^^^^^
a 400 watt light is not unuff light in that space even with lightrail
id be looking at 2 600 in that space ...go in growroom tools and have a play with sizes light ect to see what works best

as for plants id go no more that 4...i run a 3 channel try same length as your tank and i put 4 plants in each channel and veg untill they are 14/15 inch then flick the light
i do train them up and till then to get a nice evan canopy

A bit over the top though mate

If you have gunk then theres something wrong with the nutes, or you are using them wrong

And if you have algae then thats probably light intrusion

Ive never had to clean everything, only at the end of a grow, so doing it at every change is good practice i suppose but unnecessary

Back to the q though

Plant numbers is entirely up to you but as a good average 4 would be good imo

Owd

thanks y'all for your help and advice, much appreciated.

I generally clean the tank, pipes, filter etc after each grow and it seems ok.

As for the plants, i think i'll go for 4 in the tank, and maybe when the current crop of 'cheese' is done in 3 weeks, i'll pop the 400w digi ballast and bulbs on ebay, and invest in a 600w set up, it'll have to be just the one on the rail, as heat and getting rid of it would pose a problem for me (bedroom grow).

Although i'll be giving away 4 white rhino, i'll keep the faith with just the 4 in the tank and pray for a better yield.

Oh, the 4 i'm getting rid of are already rooting into 3" cubes so if any of you live in west cornwall, you can have them.

'it's got some labrador in it'.