emperor tetra

Hi guys, can someone please help me. I have a 95l tank planted tank with 4 cardinals, 5 emperor tetras, 4 rummynose tetras, 6 harlequins, 4 corydoras and a pleco. I do partial water changes 2-3 times a week. Water parameters are 0 ammonia 0 nitrites 10-20 nitrates. 4 of my emperor tetras have...

I currently have 5 zebra danios and 3 platies in my 29 gallon cycled tank, my water is soft, my ph is 7.2, my temperature is 75. I am thinking about adding 5 black emperor tetras and 5 black Kuhli Loaches. Is this an okay stock and would this be the limit to my stocking? I do have sand substrate...