HELP!! Plants not growing/purple stems

My plants are 6 weeks old (white rhino and unknown). They are in a sealed basement grow room (4X4X7). 1000 W MH on 18/6 right now. Fox Farm soil. 250 CFM intake and outtake with fresh outside air piped in. Only added tiny amount of nutrients-fox farm grow big on 2 occasions.

Problems:
Plants are growing at very slow rate. Only 4-6" after 6-7 weeks. Plants are droopy with purple leave stems and purple lines on main stem. When I water plants perk up but then start drooping in a few hours, even if soil still moist. Soil is drying out very fast due to temp and humidity.

Temperature goes from 84-87 F w lights on to 45-50F with lights off.
Humidity with lights on is around 28-30%. With lights off it is ~40-45%.
I have put bucket of water and humidifier in room and it does not raise humidity at all.

I am think humidity too low, temperature change too drastic. I dont know how im gonna control temp and humidity. Any suggestions?

You plants need a coat to warm them up at night. Your temps need to be with in 10 degrees of the temps you maintain during the day. You need to put a heater in there. If your soil is drying out to fast your plants also may be starving for water as most plants droop when they need watered. I would correct the temps right away. Then get a better soil mix that will retain some water but not to much as you are probally over watering them due to your high drainage issues. Plants dont like being watered everyday even if the soil drys out quickly.

Do i need a heating pad for floor? Should I raise them off the ground? Soil Moist? Thanks for suggestions.

many strains get purple veins as they mature

raise off the floor is a good idea

if the top inch of soil if dried out it's time to water

heater not heating pad because the top of the plant (where it's growing needs to be warm not just the roots)

Get a thermometer so you know what the temp is exactly

I dont agree with the top inch of soil being dry meaning it is time to water. There may still be alot of water in the soil under that inch or two. get a water meter and use it and know for sure when to water. I personaly will not water untill my plants start to droop but everyone is differnt and each to his own but just sticking your finger in your soil an inch is not a good way to tell when to water!

With small heater on low and exhaust still on, temp was holding steady at 70F and 40% humidity. Hope this helps.

The top inch of water is dry 2 hours after I water. I think im gonna raise lamp some.

Im still concerned about humidity being low (30%) when lights are on. Is this within range for normal growth?

I brought one inside too see if it did better under consistent temp and it has really perked up. (See pic)

Why did you spend all that money on lights but only one pot for two plants. You might be overloading your pot with roots, two plants in the same pot drink twice as much water.

hey do purple stems signify a good strain? or is it just a common thing?

Does your problem resemble any of these

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Lots of strains will turn purple if the temps are too low. Also, the cold will cause the growth to slow as well. The suggestion to warm up your grow space is the right ticket.

Also, to monitor your watering, get a moisture meter at your local nursery. It will take all the guess work out of your watering schedule.

Vi

To me it sounds like:

1. Plant Drooping = Looking at those pics. I would say heat problem - Not enough heat being taken out during day. OR, Some nutes will cause plant drooping mainly because of strength of nutes. In which case I wouldn't worry much. But get that heat outta there.

2. Check Root temp. Ideal temp should be between 65-70 degrees (F). Any temp above 72 degrees and your plant won't take up nutes as easly and minerals start to collect on roots.

3. Get and keep those plants off the floor. Place a platform of some sort under it to bring them up at least 3" above ground.

4. You need to learn how to maintain room temps. Plants do better between 74-82 Degrees (F). Day and night. Your running high temps while lihts are on, but very low temps why light is off. Change that and get those temps more even durring on and off light periods..

5. Get that other plant in a it's own pot! Or trash it!

Thanks,

Temps are now holding steady between 77-65 degrees F and looking a lot better and growing faster. Why raise them off the ground? Just curious.

You really shouldnt raise the light too much. Why do you have such a strong light for so few plants? Personal opinion: You should downsize your light. A 100 watt kept about 6"-12" over the tops works great. The plants grow more compact that way. And it doesnt look like you have too much room to spare. But a 1000 watt... You probably need to keep it about 1 foot + over the tops.

Also, do you have a glass plate (heat shield) in your light? If not, you may need even more room between plant and light.

Another thing you can do (and I highly recommend it) is a drip system. Takes all the guesswork out of watering.

And dudes right, seperate your plants into their own pots! They need individual love, like children.

You get them off the ground because the ground is a good conducter of COLD! Your pots absorb that when they sit on it. Works for dog houses too. Wanna keep your dog warm, get him off the ground.

18 to 24" is a fine distance away for your lite , even close if you have a heat shied but if your hand gets hot at the tip hieght you can bet your plants are hot

drastic changes in temperatures stress them out A LOT! they like to stay around the same to be the happiest. perhaps less than 10 degress from day to night. i noticed the leaves would curl up and get dry, but not turn any other color. this is how the leaves looked from drastic temp. change.

I have 30+ plants. I have since transplanted into separate pots.

you had them outside?

Can Anyone Help Me With My Plant ? is my First time qrowinq