Help please! Yellowing and deformed leaves

Hi guys,

This is my first grow and since about 2 days the tips of my leaves are turning yellow.
I'm growing indoor under a 100w led lamp and an extra 30w lamp for extra red and blue light.
I'm using coco coir from Canna as medium and feeding the biobizz line of nutrients together with their Acti-vera enzyme product to make it suitable for coco growth.
I've been keeping the ph of my water around 6 and i stuck to the biobizz feeding chart for coco and light-mix. So the first week i only added 2ml of Acti-vera and the last couple of waterings i've also added 2ml of Biogrow per liter of water. I water once every 1,5 to 2 days and have about a 10% runoff
It's now been 14 days after the seed germinated and came up, since about 2 days ago the tips of the leaves are turning yellow and the colour seems to be spreading.
Can somebody give me some advice on what seems to be the problem?
I think i have it narrowed down to a couple of things but im a bit anxious about trying the wrong thing and messing it up.

The first pictures are from yesterday the last ones from tonight to show the progression

Anyway i'm happy about joining your community and hope to hear from you guys!

See how the leaf tips are burnt? Sure sign of over-feeding. Back off on the nutrients.

Thanks for the response, that was the number one suspect. Would you advise switching to half dosage or watering with ph'd tap water for a while?

020grower said:

Thanks for the response, that was the number one suspect. Would you advise switching to half dosage or watering with ph'd tap water for a while?

Click to expand...

I use Sunshine Mix #4 peat-based medium, which is inert and soil-less much like coco. I don't feed any nutrients until the bottom two true leaves indicate slight Nitrogen deficiency. I then start feeding at 1/2 dose every few waterings.

In between, it's just pH water.

Give them a couple to few days with just pH'd water, and see how they're doing.

spek9 said:

I use Sunshine Mix #4 peat-based medium, which is inert and soil-less much like coco. I don't feed any nutrients until the bottom two true leaves indicate slight Nitrogen deficiency. I then start feeding at 1/2 dose every few waterings.

In between, it's just pH water.

Give them a couple to few days with just pH'd water, and see how they're doing.

Click to expand...

Awesome that helps a lot!