i forgot to mention my water change plumbing. I bought a temperature control valve since my discus like the warmer water. So the temp valve keeps the temp from going over 84F even when i have both valves fully open. here's a shot under the stand where the valves are for H and C.
on that same picture you can see where i made a hole for the pvc drain through my wall and out to the side of the house to the front lawn. here's where i placed the pvc end to drain the tank.
It has a cap to keep critters out.
here's a shot of how the temp valve looked at first, but i had to change it a bit due to the fact that it mixed both the H/C water through the temp valve. Now, it mixes them through the top side of the U which has both the H/C added to it and does not reduce the output pressure. It took some tweeking but i finally got it to where i liked it. Sry, i don't have any current pics of how it looks now so i had to settle for the old one.
i generally do not use the hose to fill up the 125 since the pvc leads directly to the U that hangs on the rim, but i added the hose so that i can fill up another tank if necessary. It use to take me quite a while to do a full water change, in my case from 80-100%. It takes me roughly 20 minutes to do a full WC now