New growth is starting o turn a little yellow on the edges.. Does it need Potassium??

Help my new growth is starting to turn yellow a little bit.. the only nutes i have given them is 5-1-1 Fish fertilizer.. I use a soil mixture of Fox Farm and
Black Gold. im sure they have enough nitrogen just not sure what else they are lacking... They are into the 5th week of Veg..

It looks like you have a leaf muncher in there with the way that leaf looks...other wise they're looking good...are you feeding them??? Nutes & cal-mag???? cuz if it's not a leaf muncher it may be a mag def...good luck man and welcome to RIU

Maybe if I wake up...lol...you want IMO an even ammount of NPK until flower...I use an 8-7-6 mixed with a 2-7-7 at times to lower the N value when her green tips start turning yellow from nute burn..and I use epsom salts for my Mag...1 tspn per gal to start, every other feeding, and the calcium is in my tap water..

Mag def and boron def. For mag foliar spray with epsom salt. For boron feed any guano or manure. Anything with chicken manure. Or even crab or shrimp meal or any bone meal. I like shrimp and crab but its slow release too. So would have to feed a compost tea after top dressing. If using guano or manure, you can make a tea with those.

Personally I try not to use any guano or manure or bone meal. My grow is more on the vegan side.

Well imma have to go buy something for my babies.. The only ferts i have right now are Fish Fertilizer 5-1-1 and then i have Indonesian Bat Guana .5-13-.2 I have never gave them bat guana yet.. I know they dont look too bad but i just want my babies healthy.. So imma go buy epsom salt to start and foliar feed them that.Im sure mine are lacking Potassium and

Ok so i went out and bought some Kelp Meal for the Potassium.
So heres what i gave them yesterday 5-27 @ 5:30pm:
Each plant was feed with this as follows:
3 Tablespoon Kelp Meal Sprinkled into top soil. For the Potassium
I then Mixed together into 1Gal water:
2 TableSpoon Alaskan Fish Fertilizer 5-1-1 for the Nitrogen
1 Tablespoon Indonesian Bat Guano .5-13-.2 for the Phosphorous.
Going to watch them this week if they still look good and show no signs of burns then imma feed them this every 10 days till i switch to flowing stage then i will lower the Nitrogen..
Just wanted to keep you all updated...