A lot of people do this and get away with it for a while. I used to do it until one day when the water corp did work on the pipes and added about 10 x the normal amount of chlorine. I added dechlorinater to the tank and filled it like usual. A minute later half the fish were dead and the rest gasping at the surface.After draining, I put a measuered amount of conditioner in the tank and then fill with hose water (I let the hose run for a few minutes before I use any of the water I it).
I'm strong, but am unable to lift buckets of water up and over to dump in the tank.
Plus it messes up everything in the tank when I do it.
I've heard of others using straight tap/hose water to full their tanks, especially when using the python so I assume it's ok
It's a risk putting chlorinated water in an aquarium containing livestock. you never know when the water company is going to do work on the pipes and they don't normally tell you. After they finish working on the water pipes, they add a lot of chlorine/ chloramine to kill anything that might have gotten into the water supply and it takes several days for this heavily chlorinated water to get used up by people. During that time you can wipe out the tank. We see it here every year, people come on saying they just did a water change and their fish are gasping at the surface or dead. The response is add a double dose of dechlorinater and increase aeration and hope for the best.
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I used a couple of large plastic storage containers/ rubbish bins and filled them with a hose. The bins were next to the aquarium. I added dechlorinater to the water in the bins and aerated it vigorously for a bit before using a water pump and hose to pump the water up into the aquarium. No heavy lifting required, just a water pump/ powerhead (I used an AquaClear 800 powerhead) and some clear plastic hose.
You can make a U out of pvc pipe and attach that to the end of the hose with a hose clamp. The U gets hung over the side of the tank and stops the hose kinking or falling off.