What deficiency is this?

Hello my plants are experiencing extreme yellowing and browning on the tips of its leafs any help would be great thanks.

Sounds like nute burn.
But without a oicture we're just going off a description that could be being explained wrong, and we'd be trying to solve a problem you don't even have.
They really need to make it so you have to post a picture in this section.

definitely sounds like nute burn

Is this in the lower leaves or the new growth?
How old are the plants?
Are they in veg or flower?
Are you in soil or Hydroponic?
What are you using for nutes?
And finally....without pics (good clear pics NOT under HPS) we can't tell squat with certainty.

Have you checked your ph and what is your ppm at? And any pictures?

Masterjunk69 said:

any help would be great thanks.

Click to expand...

Any picture would be great as well. There's about a hundred posts/day here with a variety of fucked-upped plants.

PurpleKu§h;9961972 said:

Have you checked your ph and what is your ppm at? And any pictures?

Click to expand...

pH and ppms are important IF the OP is set up hydroponic. In soil, not so much.

Jack Harer said:

pH and ppms are important IF the OP is set up hydroponic. In soil, not so much.

Click to expand...

Yeah very true. I guess I failed to ask hydroponic or soil.