When toilets do not flush fast enough, they cannot move the waste material down the toilet effectively, leaving some behind in the toilet bowl. Slow flushing can also lead to overflow, especially when flushing the toilet a second time after the water fails to go down. The slow-flushing toilet might have a clog or there might be a problem with the water level. Fortunately, all of the problems are easy to fix.
A part of the toilet on the rim might have a clog. The rim has orifices out of which the new water flows into the toilet every time the toilet flushes. Like with any opening, the orifices can get clogged with all sorts of items, ranging from minerals to dust. With a cotton swab, clean out the orifices, dislodging whatever is blocking the water flow. The water emerges more rapidly from the cleaned orifices, speeding flushing.
Toilet Bowl Trap Clog
The toilet bowl trap might have a slight clog. Dislodge clogging material by using a plunger. Before using the plunger, cover the floor with plastic so that the toilet bowl contents do not get on the floor. Move the plunger up and down quickly to create suction needed to dislodge the material. Do not attempt this if there is no water in the toilet bowl. After plunging, flush the toilet.
If the water still doesn't go down, you might need a closet auger to push the waste matter down the toilet. Insert the closet auger into the bowl trap and rotate the handle, pushing the cable through the trap. Ideally, the cable will dislodge the waste matter.
Sometimes, the blue water or bleach drops that dissolve into the toilet will not fully dissolve and a part of the drop will get trapped in the toilet bowl trap. This material will eventually dissolve, though the process can take more than a month.
You might need to change your water level. Make sure that the toilet finishes filling before checking the water level. The toilet tank must refill after flushing the toilet. Take the lid off of the tank. The inside of the tank has a fill line so that you know where the water level should be. If the water isn't at the fill line, use the float arm to adjust the water level on an old toilet. For newer toilets, the fluid master fill valve has a float assembly that allows you to adjust the water level. Either way, move the adjustment to a higher float level. Then test the toilet to see if the toilet flushes faster.
Sometimes, the small hole at the bottom of the toilet bowl that creates the jet for the flushing action can develop hard mineral build-up, which can inhibit flushing. Resolve this by taking a long knife and scraping inside the hole until clear.