Growing plants question

Hello,

I bought myself quite a bunch of cryptocoryne wendtii brown. I planted them in rows in a 2ft. I planted them in 2cm PFP with chemicult and rusted iron nails, and capped it with 2cm pool filter gravel. This was not enough to cap the gravel completely as I ran out, and to make it worse a accidentally dispersed some PFP with the hosepipe.
I noticed that if there is any water flow in the tank then it turns the water brown quickly (then no light shines through and the plants will probably die, I also dont want to start adding liquid ferts until Im sure I wont need to do daily 50% water changes to get rid of brown water), but no flow (stagnant water) means no leeching and no colour change. So for the crypts to grow do I need water flow? There will be no fish in the tank so Im fine with stagnant water, Ill just do water changes to keep the water fresh, this is purely for the plants.
Also does the water need to be heated for crypts to grow quickly?
and how well to crypts benefit from DIY CO2?

Thanks,
Mitch

 

Stagnant water will result in algae. Rather put a pump in there.

 

I would add a small pump or airstone to agitate the water.

 

cryptocoryne wendtii are categorized as low light plants, even with the brown water they will still grow.
Another perspective....
If you do not want to add a pump, i can advise is to fill the water slightly above the crypts and let them grow emersed.
Try keep the plants in high humidity by sealing the top of the tank. The brown water will also make it a bit difficult for algae

 

I just remembered Cryptocoryne wendtii are STILL listed by authorities as not permitted
( 1 of only 2 Crypts on the list):amazed:

Thus usual rules would apply regarding discussion , unfortunately.

 

so aka. blacklisted?