I used to do a 25-30% WC every two weeks or every month. Lugging 5 gallon buckets for a 55 gallon tank was a major pain, it deterred me from wanting to do it.
Now I do weekly or biweekly WC about 50%. I've got a garden hose adapter on the kitchen sink and a 50 foot hose. I siphon the tank water out the window into the flower box. Don't worry, my siphon hose has a fine net on the end that goes in the tank.
As for ferts, I just started dry dosing this week. I have been using root tabs for about 5-6 months, I bury more when growth seems to stall.
40g hex, looks heavily planted cause of one HUGE sword that takes up at least 1/2 of the tank and alot of big java ferns glued onto the decor. I do wc every other week (sometimes 3 weeks) and never dose anything.
50+% water change every 6 days. (I did some rough math, it's more like 60+% when substrate and hardscape are taken into account)
Dose GH booster after water change.
Dose potassium nitrate and potassium phosphate every other day.
No consistent micro/trace dosing at the moment - as I have yet to see a noticeable improvement with it.
If I notice any problems or need to correct my dosing, I do two 50+% water changes in a row. If my rough math is correct, and I'm actually doing a 60% water change, two consecutive WC's is theoretically changing 84% of the water.
For my 40 breeder, I do 15% water changes each week. I mix the water (about 5 gallons) and let it sit for a week. Currently, I use the following concoction:
-- 5 gallons tap water (KH 0-1, GH 2-3)
-- 5 mL API Tap Water Conditioner
-- 1 1/2 tsp Instant Ocean Sea Buffer (sodium carbonate, sodium bicarbonate, sodium(?) borate)
-- 1/2 tsp calcium carbonate (powdered)
-- 1 tsp epsom salt (magnisium sulfate)
-- 1/2 tsp calcium chloride
-- 1/2 tsp gypsum (calcium sulfate)
-- 3/4 tsp Instant Ocean Sea Salt
This gives me a KH of around 3-4 and a GH of around 11 in the tank. I also have a Ca level of about 60 ppm. Phosphates are around 4 pmm (probably from fish food -- I feed a lot of food to a lot of fat fish).
I'm going to start adding some potassium nitrate because my nitrate is currently 0 ppm.
After the water change, I dose with 20 mL of LeafZone and 5 mL Flourish (one per week). I also add 5 mL of Flourish Excel daily and recently added a DIY CO2 reactor connected to the Nutrafin CO2 generator.
I'm thinking of increasing KH a bit because, although I get KH up to 3-4 after the water change, it is back down to 0-1 before the next weekly change.
I change about 50% of the water weekly in a 180 gallon tank. The tank is dosed with either macros or micros daily and I notice big improvements when I do so. The tank water is used on the garden plants, not wasted. No way am I carrying that many buckets, I use a Python hose that is about 11 years old.