Hi Marie! I agree with fencer. I suck at doing water changes too because I am also lazy.
I have set up myself a system where water changes are super easy though, and I find I do a lot more water changes. I used to do maybe 6 water changes a year before, now I'm up to weekly!!
If you make it easy for yourself you will be more likely to do it.
You could use some of the additives without using all the nutrient lowering products. You can gradually ease into using some of the bacteria encouraging products as time goes on, and see the reaction of that. I am familiar with Zeo, so I would have to suggest these products: Sponge Power, Xtra, Amino Acid High Concentration (for SPS), and Coral Vitalizer. These four you should have no issues using on your established tank, except the latter of which I find I have to use very sparingly or I will get diatoms and cyano. You could also put Coral Snow to use which I have found is a great combatant of algae especially if used with Bak. However, on an established tank I would be careful using both of those, but especially the Bak.
As far as Zeo goes...don't follow the directions on the bottles. If it says use 1 drop per 25 gallons daily use 1 drop per 25 gallons 3x per week or even less. You should notice a different with a small amount. However, I do find that with Zeo you need to be tedious about it (I assume FM is the same way). Either do it, or don't - there is no halfway. If you do it halfway (use the additives irregularly) you will cause yourself more grief than good imo.