Thank you all for your input. I think I am going to just use a 5 gal bucket and my 44 gal brute until I can buy a piece of appropriate hose with an attachment for the sink.
I have used garden hose to fill a almost 6000g pool. System was probably close to 7000g.
I also used a sump pump to run water through about 250ft of black hosing kept on a black tarp to heat the water for free during the summer months up here in wisconnie.
Not only did I have 0 casualties, but we have eaten some of the fish, and I am still here.
It's preferable to use an older garden hose since most of the material emollients and anti-mold agents have been aged out of the hose. When using an older garden hose, ensure any standing water in the hose has been ejected before placing the nozzle end into the tank. Especially if the hose was in direct sunlight since the standing water can reach scalding temps in the sun.
The best hose to use is potable-water flexible tubing available from most hardware chain stores. It's the same material filter hoses are made from. Standard hose fittings can be attached to allow these hoses to be used/connected as would any garden hose.
Use a garden hose. Anything else is overkill and a waste of $$$. If you're really concerned, run it for a minute to clear any standing water and then fill a bucket and do a water test. Only way I can see an issue would be if the garden hose was previously used with toxic chemicals or something random like that.
I have been using an old garden hose to do water changes on my tank for over 4 years now. It is stored in my garage all year. All I do is run water through it for a few min before filling my tank up. My Clown Loaches have been fine this whole time.