While literally, the opposite is predict too much (or in some cases too big), you might be looking for overestimate. (Underestimate is synonymous with predict too little in the meaning of amount or measurement.
The opposite of 'big' is little.
Extrapolate that means to plot existing data and predict or draw a curve that for a range outside the existing data.
MinorMinor, lesser, little, small...
The opposite of 'much' is 'little'.
little chiken
The opposite of predicting (foretelling the future) would be recounting (telling the past). The opposite could also be not making a prediction, and simply waitiing for the event.
There is no way to predict this or even predict if there can be such a thing.
There isn't an opposite of ADHD par say. Schizophrenia would be the chemical opposite of ADHD since it involves too much dopamine in the brain as opposed to little dopamine in individuals with ADHD.
The opposite of small is large, or sizable. (also big, opposite of little)
A few , A little A dearth.
a little
No
The opposite of 'big' is little.
Too much extra heat, the oceans's absorb it because of the energy required to heat water by the same amount of temperature. Too little heat, and the opposite happens.
Not enough.
I would be more worried of the opposite ie. too much nitrate. To the best of my knowledge it would be very hard to get too little nitrate in an Aquarium although by using Reverse Osmosis or Distillation one could possibly make the water incapable of sustaining life.
Scientists have sensors that detect vibrations. When two vibrate from the same cause, they hear it at different times, and the difference can be used to triangulate on the epicenter. They can predict it too a little.