Help with climate control

I'm based in the UK and need some help with climate control. Nobody who knows what they're doing has ever seen my grow, it's all been done from research online.

My grow room is a 10 x 8 insulated log cabin, diagram attached. Due to the legal system in the UK I have to keep the max number of plants to 8 to be below the commercial growing threshold, at this number I will only ever get a caution. So I have to maximize the yield from 8 plants. I have a 4 veg 4 flowering rotation system, both veg and flowering and run with a RDWC homemade system, the vegging one is a simple 4.5 gal bucket recirculating with air-stone, the flowering is a 5.5 gal full waterfall system with air-stones. I use CFL's for the vegging (about 250w per plant) and mostly LEDS with supplementary HPS for flowering.

My issue is with climate control, I have been struggling to keep the humidity down (this has got better with a heater on a thermostat to come on at 60deg approx) and the temperate right. I run a 6 inch intake fan on half speed (unless its very hot out) and a 9in exhaust fan on a temp controller set at 75deg. The whole room is covered in white plastic. I use a high quality plantphotonics led panel above each plant, with a supplementary small Chinese led between each, then in the center of the room two HPS on either 250 or 400w that come on for about 6 hours a day. I have solar panels too.

I've been running this system for about a year now, adding the HPS after realizing it wasn't hot enough in there with the LEDS. I get about 22-26oz from 4 plants this way, so not shabby. But I know my climate control is not good enough so yields can still be improved.

I have looked at a few multi controllers but none of them seem to do what I need. I need the heater to come on during the day when it's not warm enough - the controllers only seem to turn on heaters at night, and I'm also worried about very cold air coming in during the winter.

Any input into what I'm doing would be fantastic - I really want the ultimate set-up I can have for this size of system and limit on plant numbers. I have been reluctant to post on any of the bigger well known forums (paranoid!) but this seems like it might be the right place.

BTW - the diagram is not quite right, with plants at full size there's is only about 2 feet from the edge of the plants to the plastic sheet that separates the room, the one by the intake fan is right up to the plastic over the fan.


Attachment 18322

And yes, I have been making the most amazing bubble hash from all the trimming - thanks Bubbleman - it's all I smoke now, nothing else is good enough!!

Do you have the space for a dehumidifier?

Yes I do, on the wall next to the door under the fan, I was just trying to use less power but if needs must

or switch the cfl's with the led's and get more hps for flower?.. wouldn't help with lights out though.

Maybe more intake would help, if possible. 2-3 passive intake?

You could also look into saving on power with HPS. Not sure your total LED wattage but the footprint on an HPS might beat the LED meaning less lights and wattage and room for a dehu..

I think it might be a good idea to swap the CFL's for the LEDs and use them for vegging, thanks for your help with this :)

You could also pluck leaves that are touching and lower leaves; if you don't or haven't tried. I hear it's humid in the UK; good luck!

Already stripping all the leaves, humidity down nearer 50-65% now, so already better!

And I'm definitely going to move the LEDs over to the vegging area and get 4 x 400w HPS with aircooled hoods, and a properly climate controller box.

Thanks again :)

Live long and prosper!