A hose and pump will be necessary to remove all water. Insert the hose directly into the tank and begin pumping into an approved container. If there is any fuel mixed with the water, take added precautions to ensure the fuel does not make contact with your body and keep in mind that this mixture is extremely dangerous.
The principle is 'dilution': with the first addition of clean water to dirty water, the dirty water becomes less dirty because it is diluted by the clean water. With the continued addition of clean water to dirty water, eventually the dirty water will be completely diluted and there will be no dirty water left; it will all be replaced by clean water.
Assuming the dirty fish tank has had fish and water in it, without doing various specialised water tests it is impossible to tell what is in it.
Gunk up the engine sooner.
when the water starts to get dirty if it is a bit dirty then leave it when it starts to get really dirty clean the filter and your fish tank
The only way to know for sure if a person has water in the gas tank is to drain the tank. Usually a car will sputter and die if there is water in the tank.
Water in fuel tank, dirt/rust in fuel tank, algae in fuel tank, plugged/dirty fuel filter, dirty fuel injectors,
What will happen if water gets inside gas tank
remove the fuel tank and drain the water
skipping stall no start
bubbles on top of gas in tank
Water is heavier than gasoline, it will pool at the lowest point of the fuel tank.
Have you tried using gas line antifreeze? That will help to remove some of the water in the gas. The best way to make certain all the water is out of the tank is to siphon the gas out, let the tank air out and re-fill the tank with gas from a station you know does not have water in the gas.