I moved your thread to the Plants section so you'll get better responses.

People on YouTube stated the Java Moss is so easy to grow, yet I have seen many people are having difficulties keeping them alive.

When you say "them", do you mean other types of moss? Or just Java Moss? Different mosses are similar but there are some slight differences in care. That said, I'll respond just regarding Java Moss.

I've tried to keep Java Moss in my tank and all failed. They just turning brown and melting away (rotten).

What are your water parameters? Lighting? Fertilizer? What have you dosed your tank with and what are you currently dosing it with, if anything?

I wonder whether the water temp will be a factor.

Yep. Mosses are cool water epiphytes. The warmer the water, the less likely one is to be successful with most mosses.

I ordered some Christmas moss online in the past and it arrived already showing in brownish color.

The seller who shipped it to you is to blame for that. Healthy moss wouldn't turn brown during shipment even after 7-8 days. That is, unless it cooked along the way or froze completely. Which... really is the seller's fault for not providing insulation. In the future if you ever see brown on moss, trim it away. If it's green, it'll grow. If it's brown, it'll spread (to more areas of the plant) and can kill off the rest.

Moss merely requires cooler temperatures (for the best conditions), decent flow - shouldn't be compacted at all, lower lighting, no heavy fertilizer dosing is required, kH and gH don't matter much, ignore pH, ammonia/nitrite/nitrate won't bother it, Excel will nuke it, some medications can be problematic. Other than that, Java Moss and other mosses really are as simple as people suggest.

I probably wouldn't try to keep it in water that's 81 degrees expecting it to thrive. But I'd probably give it a try. There's a chance it could be okay if there's enough flow and it's not constantly in high lighting. If you get some moss, maybe try a little bit of it to see how it goes instead of trying the entire portion you receive.

Just to give you a sense of how moss can grow in parameters ranging from 55 F, 4.9 pH/0 kH, 5 gH to 70ish F, probably 7 pH, 4-5 kH, 10-12 gH? Here are some photos from some of my shrimp and snail tanks through the years:

Note there was a heater in this Caridina tank above merely to prevent freezing.

For those alarmed by snails, here's a better look at what happens in some of my tanks during feeding time:

So there's rarely much in terms of anything that needs to be cleaned up. If a segment of moss begins to die, they clean it up quickly.

Most of the tanks in the photos have little to no additional fertilizer beyond what's available in a particular substrate. The only thing the tanks have in common: low light, good flow, cooler temps. Low light/low PAR tanks can also be pretty bright, as you can see.

 

Thanks Somewhatshocked! I think I had the java ferns most of time (last time I bought it from Petco and I assume they have the most common type) and the one arrived in brownish color were the Christmas type. I don't use power head to move the water in my 75 g tank, so it is only a canister filter that has been pushing the water. The water temp has always been around 80F in my tank cuz I used to keep discus in it. Now discus are in my 40 g and the water temp is around 75 in my 75 g now. There might be some left over java moss in the 75 g and keep my fingers crossed if they will start growing in that water temp. My lighting is a 48" Finnex LED for plants. I think that is too much light for java moss?

I used to use CO2 injection in the tank and use liquid ferts (Potassium, Phosphorus and Iron) once every a few days.
I may set up a 2.5 g or 5 g tank just to keep java moss to see what happen. There will be no heater in the tank. I assume moss and moss balls can be kept in the same tank, will thrive without a heater. My indoor air temp is around 60 F. Would that be fine with java moss? Can it thrive without using a light? I may be able to leave the tank on the window sill at the south side. It will get some direct sun light every day.

 

I don't use power head to move the water in my 75 g tank, so it is only a canister filter that has been pushing the water.

Try to place the moss near the filter outflow or as near as you can in the tank. That will help.

There might be some left over java moss in the 75 g and keep my fingers crossed if they will start growing in that water temp.

Might be a good idea to split it up so you can save some for a different tank like you mention here:

I may set up a 2.5 g or 5 g tank just to keep java moss to see what happen.

This is a really good idea if you have the room for another small tank. I say this as a full-on moss shill, admittedly. But you really can do some nice things with moss. It's my favorite low-effort plant.

If you don't want to set up an entire tank, you could consider a vase or even a nice jar. I like to have a few of those going so I can toss in moss trimmings to let them grow out.

I assume moss and moss balls can be kept in the same tank, will thrive without a heater.

Definitely.

My indoor air temp is around 60 F. Would that be fine with java moss?

Not just fine but probably ideal.

 

I've never kept a shrimp tank. Your shrimp tank looks beautiful! What kind of the substrate in your shrimp tank?
I haven't seen any Java Moss or Moss balls in my LFS. Would you recommend any reputable online stores for them?
Do you order shrimp online as well?

 

What kind of the substrate in your shrimp tank?

There are six different shrimp tanks depicted in those photos. Light stuff is pool filter sand. Darkest is ADA Aqua Soil Amazonia (original stuff from 2012) that's in two different tanks. Tan is Double Red Line Akadama from Japan. The substrate in the long tank at the very top of the post is a product called UP Aqua Shrimp Sand.

I haven't seen any Java Moss or Moss balls in my LFS. Would you recommend any reputable online stores for them?
Do you order shrimp online as well?

If you can find tissue-cultured moss, it won't matter where you buy it because it will be great. But short of that? I'd start in the For Sale section (we restrict buying/selling to that section) here on the forum and with other hobbyists in local clubs or social media groups. Buying from other hobbyists gives you a chance to see the actual tanks where plants and shrimp come from, learn about a person's tank husbandry practices, understand overall health. You also tend to pay less and get better plants and shrimp.

I don't order shrimp from retailers online because they're 99% of the time fresh off importation. That means they're adults and won't have as much lifespan left as juvenile shrimp from a fellow hobbyist.

May seem daunting at first but just keep poking around and you'll be able to discern who has quality plants and shrimp and who does not. That's whether it's here on the forum or on a Facebook group.

 

Hi All,

I've tried to keep Java Moss in my tank and all failed. They just turning brown and melting away (rotten). People on YouTube stated the Java Moss is so easy to grow, yet I have seen many people are having difficulties keeping them alive.

I wonder whether the water temp will be a factor. I have a 40 G BB breeder tank with two discus in it. The water temp is at around 81F, ph is at 7.2 and nitrate is around 10 ppm. Will Java Moss survive in that tank?

I ordered some Christmas moss online in the past and it arrived already showing in brownish color. It was ridiculous.
I appreciate any comment.

I’ve never thought I see hear about Java moss being an issue lol. But again I’ve had simple things fail plenty of times myself. I’m going to presume that you know a little bit about water and your not pouring bleach in your tank and say my guess is the moss itself has a Disease or it’s also possible that something is getting into the water column. Be mindful when spraying chemicals anywhere close to the tank. Including air fresheners.

I lost a few tanks from clean with Lysol spay bottle about 6 feet away and it got airborne into my tanks. Killing off my beneficial bacteria, causing mass ammonia/nitrites to spike.

I hope you figure out what’s going on and it gets better

 

I ordered some Christmas moss online and planning to put them in a pickle jar (without the pickles). Should I leave the top open while the moss is in it? I heard they don't need air. Is that true?

 

I have 2 1 qt Mason jars of Java Moss from hair cuts sitting on a window sill but no direct sunlight. No lids also. I top off water when needed

 

Here is the Christmas moss I received in the mail yesterday. I do see some yellow/dead ones and hopefully the moss will start growing. I will leave it alone and top off as needed.
Let me know if I need to do anything to them.

 

Let me know if I need to do anything to them.

"Them" - do you have multiple types or portions? Asking for the sake of making sure we're giving you good advice.

Trim of all the brown areas so any dead or dying parts don't spread.

Loosen those clumps up - maybe consider keeping it in two separate jars. The less crowded the moss is the more it will be able to grow for you.

Give the jar or jars a little swirl once or twice a day when you walk by to keep things moving a and less stagnant.

Swap some water every few weeks to keep things fresh.

Let it do its thing.

 

I ordered Christmas Moss and I assume that is what they gave me. The dead moss will spread?

 

Yes, as mentioned previously in this thread. It can spread.