Water parameters were good. I'm sure it was from transferring tanks. I had to move them to my 10g guppy tank because their tank is cycling and hopefully growing all the micro food you are talking about
So it is a new tank. It takes time. Me not especially being the scientific research type, I can't say how long. If you have any rocks or decorations which might be older from an established tank. Those will have some biofilm on them. Wait to move them over until your tank is established after cycling and stable not having spikes of any kind.
This might be a little bit. You can even move a few fish into the new tank after cycling, for a while to season it, and get the biofilm established before moving the shrimp over.
I haven't ever put Dwarf shrimp into a brand new tank, only ones which had been running for a few months to years, with fish in them, until recently. The tank had been up for a couple months, started with BB filter pad and snails. But they are looking fine and there are many plants and DW and a couple rocks in the tank too for them to pick on. 12G tank for 6 Blue Velvet shrimp, lol. But the star attraction will be Tangerine Tiger Shrimp, coming soon!!!
You might also be able to grow some "algae" rocks in a window sill.
Get a clear thin glass vase (from your cupboard, thrift store, yard sale), I guess a jar would work to but not be as decorative, big enough to hold 2-4 hand fulls of rocks.
Get some river stones... clean well to make sure there isn't any weed killer/ pesticides/ weird living pond creatures, or chemicals from a factory, depending if you get them from your yard/decorative rock landscape supply company, creek, craft store or fish store.
Gently put the rocks into the vase and fill to a normal level with fish tank water you would be getting from a pwc, you want it with the ammonia and food, doesn't have to be very dirty water. It is a little natural fertilizer.
Then set it into a sunny window, the more time in the sun the better and it will start growing algae. Then top it off with new pwc water whenever you need to refill due to evaporation. It should start growing you some algae on the rocks, then you can add these algae rocks for your shrimp on a regular basis, rotating them in and out as they pick them over.
Fish like it too some times, and of course Otos and Plecos
, so you can make your own supplement for them.
If the water happens to ever get smelly just change out the water and rinse with new pwc water.
You can add a Arrowhead/Pothos (possible irritating sap), Chinese Evergreen (toxic seeds and some parts), Anthurium, Peace lily plant (also have the insoluble calcium oxalate) in the top or some other kind of house plant cutting to give it additional interest. If you use a fresh cutting, put it into a different cup/drinking glass/jar/vase in water until the cutting part kinda heals up. This is a precaution, in case the plant has any drippy plant juice oozing from the stem, so it wont get onto your algae rocks. Some plants have irritating or mildly toxic sap. I have used the Arrowhead plants for years in my fish tanks, also personally used the Anthurium too and planted bowls and never had any problems.
Disclaimer: Check if you have kids or cats or dogs (pets) about if the plant you might want to use would have toxic leaves, berries or sap. Here is a link in case you might be interested. Most all the common house plants have some issue.
Toxic and Non-Toxic Plants | ASPCA
