I need some help figuring out what’s wrong with all my plants, I’m lost

I’ll include some pictures. But all my plants are turning brown and seem to be dying. It doesn’t matter what they are, they’re browning and dying. Amazon swords, foreground plants, etc. On top of that it seems I have either hair algae or a fungus growing on some.
It’s a low tech tank with eco complete substrate. Parameters are stable and fully cycled. I started dosing Flourish Excel to try and help the plants as well as get rid of some of my algae. I’ve also started using Thrive fert once every couple weeks. Last but not least I’ve added root tabs. Everything seems to be getting worse and can’t figure out why. Pics attached.

 

What lights do you use and how long do you keep them on? Too much light leads to excessive algae growth.

 

The brown looks like algae. May want to get something to eat the algae. The excell should help. Do you feed the fish a lot? How high are the nitrates? How often do you change the water and how much do you change.

 

The brown looks like algae. May want to get something to eat the algae. The excell should help. Do you feed the fish a lot? How high are the nitrates? How often do you change the water and how much do you change.

I try to only feed them every other day. Barely anything hits the ground as they devour the majority of it.
Nitrates are hovering around 5, sometimes a little higher. I was changing water every week but now have been every other week due to my schedule. I do a 25% water change typically.
This all started with an algae bloom but now my plants are dying. I’m out of ideas.

 

What lights do you use and how long do you keep them on? Too much light leads to excessive algae growth.

I’ve got a Nicrew on my 46 gallon. Lights are on about 10 hours.

 

Looks like staghorn and diatoms in my opinion. You can use a syringe and dose straight hydrogen peroxide (3 or 6%) directly onto the tufted algae and it should kill it. Remove manually what you can first. As for the diatoms they are common in new tanks, if that's the case its likely they will fade in several weeks or a couple months. If it's been up several months and is now appearing there's a lot of things that "might" cause it but light isn't usually one of them.... you can probably rub it off as you syphon water out for water changes and then it's often useful to do larger more frequent water changes and more frequent filter cleaning and replacement of polishing pads and fine floss type media as diatoms can actually continuously supply themselves through the floating bits of themselves (not sure how to simply explain them recycling themselves lol).

Causes can be anything for that combination, I'd start with root tabs and reduce lights to about 6 hours or two 4 hour periods with a 4 hour break between. Appliance times are awesome and cheap to accomplish breaks and accurate times. Make sure you're placing root tabs a couple inches away from the base of the plant at least.

Getting rid of it temporarily without fixing the issue will just mean you work on the same issue weekly. Make a change and wait 2-3 weeks minimum before making any more after a cleanup to see if what you changed is working or I'd it was a bandaid.