My Xmas moss has started to turn brown

[Ecalyte]

Hi everyone,

I bought 2 xmas moss walls from bioplast, 3 driftwood tied with xmas moss from c328. They were doing fine up till about 3-4 days ago. Previously been in my tank for about 3-4 weeks (maybe longer).

They've started to turn brown.. and at an increasing rate.

My tank has zero ammonia, zero nitrite, and 10mg/l nitrate.

I use ADA II Amazonia, and I run a chiller that keeps the temperature between 22.5-23.5 deg. (Chiller set at 23 deg).

Are they transitioning from emersed to submerged form? I really doubt it as they've been in the tank for a month or so, and would have done that earlier right?

This is really making me frustrated..

Can anyone shed some light on this? I want to purchase some mini x-mas from a forumer but I'm afraid it's my water that's bad? What parameters should I test for?

Also my tank is 37x21x21cm.

[Ecalyte]

Also to add.. I have a US fissidens wall in the same tank that is doing fine, and some mini fissidens and US fissidens on rocks that sees a bit of pearling after around 4-5 hours of light and CO2 exposure..

This is a CRS tank with CRS that's been there for 3 weeks without dying..

Now that I think about it.. the Xmas moss has to have been in the tank for more than a month! Around 5-6 weeks..

I've also been dosing it with Borneo Wild Lush liquid fertilizer...