Need help with plants Please

[Lazien]

This is my first time with plants and I feel like I'm failing badly.   I will be thorough since I have no clue what I am doing wrong and maybe more information is best.  

I got my plants from the coop 10 days ago and planted them in my 20 gal tank that night (first picture).  I forgot to take out the purigen from my HoB filter so all of the fertilizer I put in that night was gone the next day when I tested the water after work.  I realized my mistake and removed the purigen and added 2 pumps of easy green, a couple hours later I noticed it was barely showing up on the test strips and added another pump.  I then proceeded to add 1-2 pumps a day (for the next 3 days) of easy green because it seemed hard for me to keep it at 25ppm nitrate.  After the first 4 days of fertilizer issues I have kept the water at ~25ppm nitrate per coop strips with the other water parameters below.

I planted all of the plants as shown in the first picture using the coop plant weights for many of them except the crypts.  I put root tabs under the crypts, bacopa and pogostemon per the coop website instructions for each plant. 
I know plants melt when you get them because they have to convert but almost all of the crypts have turned into translucent tendrils (see crypts pic) which eventually floated away or disappeared completely, only 2 tufts of the initial 10 are left. 
The Scarlet temple has lost many of its leaves working from the ground up. 
The baby tears are just a mess of brown at the base with most of it sickly or dead looking. 
The pearl weed is starting to look like the baby tears with it melting at the bottom. 
The Bacopa has major melting of its leaves with lots of them falling off daily.
The Pogostemon is looking the same as the bacopa with it losing leaves daily and brown at the base.
Lastly the micro sword is starting to turn brown at the base which is hard to see in the picture.

So I would like to ask anyone willing to help what I did to kill all of these plants or are they still melting? 
If the plants are still melting, how long does that typically take?
Could I have killed the plants adding the plant weights?  I was careful trying not to crush them.
Do I have bad water parameters?  It should be noted that I do add aragonite and pharmaceutical grade pure 100% calcium carbonate to increase hardness for my guppies. 
I have my nicrew set to the second highest light setting, should I max it out?
Should I try to keep the nitrate higher than 25ppm?
Did I mess up my plants with the purigen the first day?  Did the 3 days of dialing in the nitrate kill them?
Could my 2 pepper corys, 1 female betta and 9 guppies be killing them?
I have my hang on back set to the lowest setting with a airstone in the other corner, could that still be too much flow? or not enough?

I have watched literally hundreds of hours of coop videos and read George Farmers Aquascaping book and thought that would be enough to start with success....guess I was wrong lol.

I really appreciate any and all help anyone is willing to provide as this is starting to get to me if I killed $50 worth of plants from something stupid. 
 

Aquarium Parameters

20 gal tank 24"x13"x16"tall with AquaClear HoB and Nicrew full spectrum led light

Water Parameters - Nitrate 25 - Nitrite 0 - Hardness 100-150 - Buffer/KH 80-100 - PH 6.8-7.0 - Chlorine 0

[Ken Burke]

First and foremost: don’t panic. Your tank looks great, but new.  sometimes it takes a little while to get things going.

I don’t suspect the purgen in the least.  I have used it with planted tanks in the past without any issues, and don’t think it impacted your nitrate level.  I don’t see any fish in the tank, so suspect the bio load is very low.  I’ve noticed that in my new tanks it takes a little effort to get the nitrates up.  Further, you likely don’t have mulm built up in your gravel, so the only nutrients in the substrate are from your easy root tabs.  
 

I recommend floating your stem plants for a few weeks before planting.  This will enable the plant to put out roots.  Your scarlet temple already has started putting out roots, so it won’t take too long. I circled the the spot below.

 
 

You guppies and betta will enjoy having a few floating plants as well.  I keep water sprite floating in a few of my tanks, and in my summer tub.  
 

Crypts can be tricky to get started, so keep trying.  Once you get them established, they are great.

Your water flow is fine, and I suspect your lighting is gtg as well.  
 
As with most things aquarium, patience is key.  Stay the course, and keep trying.

 

 

[K McZongo]

How long has the tank been setup?

Newly purchased pearl weed usually doesn't mix too well with corydoras. In my experience they usually uproot the new plants before their roots get going.

I found the best way to get pearl weed going from a new pot was to depot it and get it floating. Once it starts taking off and rooting you can plant it. Also note once it gets going to will shade out anything underneath it.

Like Ken mentioned having a bit of mulm or a "seasoned" tank can increase your success with rooted plants like crypts. 

Looks like you got Cryptocoryne Parva and split it up? In my experience they will take a lot of time to recover and fill in. I did the same back in 2020 for a new covid tank setup and they yellowed a bit then recovered. Unless you are running CO2 I'd just make sure the crypts have some tabs underneath.

Also, just like when most folks start out keeping fish and you may end up killing a few. You will experience the same with aquarium plants.

[Lazien]

The tank has been setup for 5+ years but I out the old decor and put in new gravel and dragon stone about 2 weeks before the plants arrived.

I will try floating the pearl weed and see if it recovers.

I did split up the crypt because when I took it out of the rock wool there was tons of snail eggs in it and I didn't want them in there.  The crypts do have root tabs under them.

 

Thanks Ken and McZongo for the help, I do appreciate your replies.