I need help coming up with a feed chart for mephis...

Honestly no ones going to give you a auto flower feeding chart because there are too many variables to take into consideration. I would start them at 1/4 strength nutes day 7 to day 10 as soon as you see the first true set of serrated leaves it should put you in the 200-250 ppm range or 0.20-0.25 E.C.. Then increase from there 100-150 ppm per week if they respond well by showing growth. Just keep an eye out for signs of yellowing or brown in the leaf tips a sign of nute burn which means back off on your nutrients. My best advice would be to check out one of the best growers on GD "Hawkbo" he does his grows in Coco Coir and has a number of Mephisto grows under his belt. Feel free to shoot him some questions he will reply. Take notice of his nutrient PPM per week to use as a guide. When using PPM you need to keep in mind that not all TDS meters use the same conversion scale so someone in the EU may be using a different TDS scale than someone in the USA. This can cause issues. With autos less is best when it comes to nutrients you can always increase them if the plants showing signs of needing more. Lastly I would recommend to Start using a Cal/mag product and add it into your nutrient regime. Hope this helps guide you in the right direction.

With mine I don't feed until they're about 3/5 nodes high. Then I start with 1ml perlitre biogrow. (with coco I guess you would start with 2 and probably when it's much younger as they're are no nutrients at all in coco). But yeah then just slowly increase the dose and add the others when necessary. They're are loads of charts on Google for feeding schedules! 🌱✌️

I personally feeding around 1.2EC before flowering , 1.4/1.6EC during stretch, 1.6/1.8EC during flowering and 2EC late flowering. You would be surprised to see how much nutrients a auto can eat . As you can see their is no chat for you there BUT a nutrients amount to respect based on the EC which means that you'll have to mix basics nutrients and additive to reach these values

Tell u right now autos u don't feed much. Start at 1/8 then bump up to 1/4. If its a heavy feeder needs more 1/2 is max of manufacturer recommendation feed chart. Gh has one u need to use the drain to waste

I have grown a few autos and started off feeding them low doses and working my way up. I would maybe try looking up the GH flora feeding chart and starting with 1/5-1/4 of what they say and if you don't see any burnt leaf tips bump it up a little more. Once you start seeing some burnt tips back off a little on the nutes until the plant grows more and then bump it up a little again. Getting slight nute burn isn't going to hurt the plants enough to cause issues. Seeing as you are in a soilless medium I have a few tips in general. Feed every watering once the first true leaves are decently formed(usually 3-5 days for me). Make sure to keep the soilless medium wet and don't let it dry out. A dry soilless medium can affect the root zone ph and lock nutrients inside itself causing issues. When the plants are a bit bigger always water so that 20% of your total watering volume comes out the bottom of the pots as runoff. This helps clean the medium of old nutes and allows you to monitor the ph of your medium. If you do happen to run into what looks like a deficiency or excess always check runoff ph. If your ph is too high or too low out of the optimal range it can cause all sorts of issues. If your ph is good then adjust feedings accordingly. One of the best things about soilless mediums is that you can easily reset the medium by doing a big flush(using properly phed water) until the water coming out as runoff reads the same as the water going in. Good luck!