I bought an $8 jar of safe over a year and a half ago and I'm only halfway through it. That's with doing a 50% WC weekly on my 110G and dosing safe for the entire volume. I spend more in a week on food than I do on dechlor for an entire year. I also use my python by turning the sink on to get higher suction to remove all the visible waste, then I shut the sink off and let the syphon remove the rest of the water. It's a little slower but I'm not wasting extra water either. When I go to refill I start to add the water back in and then slowly dump the safe and my salt right into the water flow so it gets mixed immediatley. Never had a problem doing it this way.
almost exactly what I do .. except I use aquasafe.. so I go threw it faster.. but I still spend way more on other aspects of the hobby then conditioner. I also "eyeball" it... It really depends in the end with what your working with to begin with.. if your source water is "horrible" you need to take more active stpes in conditioning it then if your say on a well and have to only worry about heavy metals or other "random" contaminents then chlorine... or chloromines. been useing python/syphons since undergravel filters and whispers where "the way to do it right".. hooking it up to the faucet was just genius imo. also if your concerned you can trickle it back into the tank and dose... or even fill the bucket right there and dose as you go so you don't have to lug buckets... I've done that a few times when mixing saltwater for my old tank. So they are extreamely multi-functional and imo more of a necessity then a want when dealing with multiple tanks or anything in the 50+ gallon range. easier water changes are the more your likely to do, so even if it adds one step easier imo it's worth its weight.
You can also purchase the tubeing ect from a hardware store and get the attachment for your local lfs if the hardware store doesn't have them for usually less then the "kit" costs... may nor "match" but pinches pennies. atm I have an old python hose ( got it when they first hit the shelves) the faucet attachment finally cracked on me this winter. ( my own fault left it outseide.. and then dropped it, and it pretty much shattered) so instead of spending the $ on a brand new one i just bought the faucet adapter for i think 10$.
I've lived in areas where our water was bad... even the local shops had issues on occasion because of just how un-fishy the water was. and other areas where it was a fish-keepers dream..
I generally shoot for a 50% wc so eyeball the dose for that amount of gallons, sometimes i'm sure i overdose.. and...well yeah i prolly just overshoot it.. But I would rather have to spend the extra 1$ or so because i go threw it faster then replace fish from being to stingy.
99% of the threads you see here with fish issues are results from
1. improper stocking
2. improper water changes
3. improper filtration
water changes can impact all of these issues.. and there is a reason when issues arise one of the first questions is what your water change regime is.. and your water test results are. imo i'll go stingy on other things before water changes..
My question is with all the benefits why wouldn't anyone have one? Most of us have spent way more on our stock,filtration,tank itself, food..
Reguardless.. just my 2cts...