It depends on what nutes you're using, how sensitive your strains are, what soil you're using....etc etc.
You should always start out slowly with nutes and increase the dose over a few weeks.
Read your plants, they will tell you what they need when they need it.
Totally. Ive been using ph paper and no meters for the last two grows. Meters only seem to last about 8 months here. Then it's time to throw down another 100-200 $.
Any meter is going to be an excellent tool to help you grow. If it is going to strap you for cash though, you'll be just fine without it. PH paper however takes a little while to get down. A good idea would be to get some ph paper while you have a meter. Test the paper to the meter and see what colors equal what numbers. Then if your meter goes down, you have a backup you are experienced with.
Just always start weak with new nutes or plants. You'll see what is wants pretty quick.
The good thing about the tds meter I used in the past was that it brought a nute mixing mistake to my attention before i fed it to the plants on a few occasions.
Accidentally mixed 2x strength, the meter read was beyond it's range and i knew i fucked up. Threw it out and mixed again.
Good luck.
