I couldn't help but stop by to make a comment on this topic.
Firstly, you have been given sound advice about keeping fish with shrimps.
Secondly, I have personally seen with my own eyes, Cardinal and Neon Tetras attack shrimps.
They "used" to live happily together. Then one day they turned shrimp murderers. Not 100% sure what triggered it. My guess was they tasted a dead shrimp one day, and grew an appetite for them after that.
Sure the adult shrimps don't fit into a Tetra's mouth. But have you seen a Lion swallow a wilderbeest whole? No! They bite chunks out of it. Same with the Tetras, I saw them 'hunt' the shrimp, circle it, each taking nips at the legs and antenna until the shrimp was dead.
Same goes for all fish. Even if you think it's too small to fit in it's mouth.
I don't know how much shrimp are where you're from, but shrimp here in Australia is expensive, because of lack of supply. I'd rather not take the risks with my expensive shrimp.
Thirdly, the fish you have really need different water parameters to shrimp. Technically, the Tetra & Pleco would prefer acidic waters high in tannins and humic acid similar to amazonian waters. The molly, SAE, and danio prefer different parameters again. Arguably, you can train them to live in the tank parameters you have. But it's not ideal. Shrimp however are not going to be so tolerating depending on what shrimp you get. Assuming your tank is slightly acidic to neutral (what's your pH), then the best option is only cherries, which will tolerate higher pH values.
Fourthly, the temperature requirements for fish are vastly different to shrimp. Your tropical fish need warm waters approx 26degC.
Cherries can 'survive' 26-30 degC temps, but it's not ideal. Forget Crystals or the more exotic Caridina genus.
Notice I said survive, not thrive. The Cherry or Neocaridina will survive in such warm temps. But they do even better in cooler 23deg C temperatures. Their colours improve, risk of catching diseases decreases, less susceptible to ammonia, they will be more active, and baby shrimps have a higher % of survivability.
Fifth, dosing fertilisers into a tank with shrimp is not advisable. Certainly not the EI method. A shrimp tank should be simple drift wood, and mosses, and any plants that don't require much light, CO2 or fertilisers. Fertilisers themselves might not kill the shrimp immediately, but it's the build up of dissolved solids that will eventually kill. Too much CO2 will kill, however. This can be maintained however ... with stringent water changes and monitoring of TDS. But then, why dose ferts when you need to be throwing it out again at water change to maintain shrimp friendly water parameters??
You won't have such issues with a planted fish tank.
A shrimp tank should really be a shrimp only tank for ease of maintenance and the comfort of it's inhabitants.
The moral of the long story here is ... think about your tank inhabitants. Don't just think about what you'd like to see in the tank.
Just imagine if you got thrown into a room with Lions in it. Oh sure lots of hiding space has been provided. The temperature is an uncomfortable 45deg C in the room. Extra CO2 is pumped into the room, for the plants you hide in (from the lions), cause it's good for the plants. But you like O2, oh well. the plants come first.
Will you survive? Yeah maybe, by hiding alot. Will you thrive? No.
Same goes for your shrimp buddies. Put the livestock that is in your care into an environment that is suited for it, so it can thrive without being in danger from fish.
Yeah I know, it's a stupid, over exaggerated example. But it's essentially, what you are doing to shrimp.
If you want to add fish (Really? After all that
) , find ones that are small and will accept the same water parameters and temperature.Suggestions: based on the fact that shrimps spend most of their time on the bottom, you want fish that spend most of their time in the upper regions of the tank.
Spotted Blue-Eye Pseudomugil gertrudae, Threadfins and Endlers are good suggestions.
Ottos are safe and cute, but let's admit it. They are boring as batshit to watch in a tank.
Tetra's are out, for the above reason. And have you seen the teeth on Tetras? Google it. They are like mini piranhas.
Cory's of any kind are out too. They don't go outright to hunt for shrimp, but being bottom dwellers, they inadvertently bumble their way onto shrimplets and hoover them up.
There you go. Many good reasons to heed the advice first given.
If you still proceed down that path of keeping fish with shrimp, you know the risks. All of it, not just that fish might eat shrimp.
Hope this helps with your decision.
Well said Vijendra sir and JayC 
