can someone please explain to me the basics of "flushing"

Flushing is used to flush the salts and deposits from the soil.
If you have drainage it will most likely not over water the plant. Not 100% sure on that.
But you flush ever 2 weeks to get the salts out, and at the end of your grow to get the nuts out of the plant so the nutes are not in the plant when harvest.

 

Overwatering happens over time with a larger plant, seedlings within a week. If you have perlite in your soil, it will retain the correct amount of water and let the rest drain off.

The more perlite you add to your soil, the quicker it will dry out. I don't add perlite to Ocean Forest, only lime. If you add dolomite lime to your soil and don't overdo the nutes, then your soil will maintain a balance. I don't flush unless problems come up.

Pre-harvest flushing is a sensitive matter, some people swear by it and others (like me) consider it an unnecessary stress at a critical point in resin production. Contrary to popular myth, unflushed pot does not burn dirty, does not crackle and pop, and does not leave black hard ash. It is every bit as good as flushed pot, if not better.

Basically, I'm saying that flushing can be avoided, but if you must flush and you have municipal water, leave a cup of water out for 2 days. Then fill a fresh cup and smell the difference. If you smell chlorine in the fresh water, then you should fill a storage tote and throw a few airstones in there for a few days. No chlorine? good to go.

 

You know when you sweat from exercise...say you don't shower right away all that sweat dries up white on you right? Its a salt build up on your body. When you wash its removed off your skin.

Salts and other materials can accumulate in the soil the same way you just don't see them. When you flush your removing those materials. When you nute you replace it. In nature that happens naturally as the rain water saturates the soil and pushes out those accumulated deposits. The same thing happens when you flush your plant.

I for one do not let my water sit out. Never had a issue with it. Its much more important to make sure your water is PH balanced. You eat veggies that are watered with grey water. Plants in nature are bathed in rain that for the most part has tons of pollutants. Every wonder where the millions of tons of dirty air that comes out of America's coal plants go to? They go into the atmosphere and come pouring down in the rain on America's crops.

 

You cannot overwater in a single watering because excess water drains out. Overwatering comes from watering too frequently, keeping the soil constantly moist and not letting it dry out between waterings.

 

This has dick-all to do with plant biology.

There is a huge difference between the clay-based soil in your backyard and the peat-based soil that most indoor growers use. An IMMENSE difference in nutrient capacity. I don't mean to be a dick, but you really need to do some research on cation exchange capacity before you get diarhea of the mouth.

Why is it more important to make sure you water is ph balanced? Soil PH has less to do with the water you give it than it does with the chemical reactions that determine the actual ph of your soil. Also, giving your plant municipal chlorine is a bad idea.