Hi henry here.
I am new in his formus hope you dont mind that I share some of my experience on planted tank with you guy. I have around 10 SAE and otto in my 3 ft tank and they are doing a good job. Howver if you dont like both the fish. Maybe you can try Yamato shrimp or malaya shrimp. From my observation, i find that Yamato shrimp did a better job than malayan shrimp. If you dont like shrimp maybe you also can try thailand rocket or three strip pencil fish. As for apple snail, i have a very bad experience with them. Indeed they did a good job, but they also helping me to pull out some of my mini ricca which i was too shock to see that and i give them alway. But overall i find that otto still the best algae eater than the others.