New Grower with a couple questions

Hey everyone
I have a couple questions,
1) at what point (size/age) should i be putting my plants to a 12/12 cycle?
2) is there a way to tell the sex before the 12/12 light cycle? and if not when they pre flower in the beginning of the 12/12 cycle what is the tell tale signs of males/ females? I heard white hairs for females and balls for boys. Does anyone have a picture of what each might look like?
3) I have gnats in my grow room. whats the best way to get rid of them? and do they hurt the plants?

thanks

 

also I have been using the flurotubes for aquarium/ plant growing and its been working but should I be using just a cool white tube or somethings?

 

I am also someone who is trying to learn this amazing art of growing. I have been reading alot so I will try to answer your questions.

1) When they have reached about 20-25 inches tall. (please keep in mind that my reading has been done in the hydroponic area. could be different for the soil method.)

2) The only way to identify the sex of a plant is to check their flowers in the flowering stage. But there is a way around this. There is a way to check the plants sex before actually throwing it into the flowering stage. Cloning. If you clone your mother plant and put the clone into the flowering stage you can then identify whether or not it is a female plant. If the clone is female then the mother in which the clone came from is a female also. The clone has the same genes as the mother plant therefore has the same properties, such as sex.

3) I don't know if gnats damage plants but I sure as hell wouldn't want them in my garden. You should be able to find a pest killer at a garden supply shop that should take care of them without damaging your plants I think.

I hope this information was of help. Couldn't help notice nobody has answered. Hate it when that happens.
HAPPY GROWING

 

all that advice is good and sound. My only suggestion would be upgrade the lights to at least a compact fluorescent.There cheap at any home depot
The gnats dont do the damage it there larva that do. They eat the plants fine root hairs. I find the best controls are either hot shots no pest strips found at any wallmart or no pest yellow sticky tape

 

You can put a plant in flower whenever you want.. sometimes this can be done later to grow BIG plants or to fill out a screen.. if you are growing in a small space you need to keep in mind the streach a plant will have when you put it in to flower.. witch could double or more in size.. and if space is no concern look for preflowers.. this is a good way to determine sex before flowering and maturity as well as alternating nodes. i will toss in a pic of an early female flower for ya. also gnats.. uugh.. they are a pain.. but an easy way to take care of this is to take a mosquito dunk and crush it in to powder and take a small amount and mix it in to the top layer of the soil in the pot and sticky traps..and do away with and standing water. good luck with your grow!