Heat & Humidity advice please

Hi guys can anyone give me some good advice please??
i,ve got my baby 1 inch plants in my tent now and i got Heat & Humidity problems
i,ve got a 600w light on the go and its about 3 feet above the plants but i cant seem to get the Heat & Humidity right, i,ve got a good fan to take the heat out the tent but when i put it on to get the temp around 27 it takes the Humidity down to nearly 0-20% i,ve put a jug of water in the tent and a damp towel and turned the fan off for now to try and get Humidity up but i know the temp with rise fast.
i have pointed a small fan at the plants to try keep them cool and that seems to have dropped the temp a little but cant seem to find a happy middle range
i,ve got my temperature and humidity meter on the pots with the plants under the light is this the right place to have it??
what are the min and max ranges for small plants??
any advice would be good please

I have heard that a wet towel hanging in your grow room will increase the humidity, watert filled trays work decently too., mayby a bucket of water sitting behind your fan?so it ccan blow the moisture throughout.

This is one of the problems with tents. You can use a cool mist humidifier. Also try 2-3 qt pans with a roll of paper towels standing up. Pour water over the top of the roll and keep it wet. I have 2 humidifiers and two of these towel setups in my closet.

I would get a cheap timer from walmart. I put everything on timers to get control. Have your fan kick on for a few minutes every 15 minutes or whatever length of time it takes to properly regulate the temp and still keep your humidity up. You ventilation fan may be too strong too. It should take a couple of minutes to completely circulate all of the air in your grow area.

My min and max range I use are 50-70% humidity during vej and try to keep it under 50% during flower.