Whats the best substitute for Hydroguard? Companion? Florashield?

So been out of the game for a while and always used hydroguard back in the day and now that Im at it again i see that its off the shelves now. Ive tried going without and have been using h202 instead to keep it clean but would much rather be using something else more natural. Anyone have any suggestions?

Hydroguard is still available - I just bought a a gallon last week.