The only thing that can not be overdone

Is balance. 

In regenerative and sustainable ecosystems anything can be applied to excess. 

Water can be excessive. So can oxygen. Or CO2. Or calcium, seaweed, biochar, humic acid, rock powder, liquid fish, crab shell, limestone, gypsum, manure, fertilizer, pesticides, and anything else you might name. 

You may have heard someone make a comment to the effect of “You can never apply too much of…(insert product here). 

You can be certain someone somewhere has done exactly that and suffered the consequences. Because there are always consequences of excesses. They are usually significantly worse and more difficult to deal with than deficiencies.