If you have a large tank such as 75 gallons or above, doing a water change can be a time consuming chore.
An easy way to speed up the process is to make a high volume water change system. This consists of a water pump, 1 ¼” sump pump hose and a few plumbing parts.
I like to use a submersible pump rated for around 1000 gph. A Danner Pond Mag 9 works well for this. I use the pond version because it has a longer cord than standard pumps.
A 1 ¼” sump pump hose can be picked up at your local hardware store. They should come in 20ft sections and can be extended by connecting multiple sections with 1 ¼” barbed couplings and stainless steel hose clamps. You will also need plumbing fittings that will attach your pump output to the hose. Buy enough hose to pump the water from your tank to outside, a toilet or a large floor sink. Pumping to a regular sink can be risky since the drains are smaller.
I additionally like to put a 2ft length of 1 ¼” PVC pipe on the other end of the hose to help add some weight to it in case I am pumping into a toilet.
If you have a maintenance business and have varying distances to drains, you can put union fittings in between the hoses to make them easy to shorten or lengthen. I store all of this in a Rubbermaid 30 gallon trash can and move it around with a flat cart.
When using this, I will use my regular vacuum hose to clean the gravel, then use the high volume setup to drain out the rest of the water for the water change. I will then fill backup with the vacuum hose.