I have a 36 gallon tank i do a 5 gallon water change 3 weeks out of the month. One the fourth week i do about a 50 percent water change, is this good or should i do more than 5 gallons on the first 3 weeks. Every week before water change time i use the vac on the gravel as well. Just looking for some guidance as to wether or not im doing ok with my tank.
Depends a lot on your nitrate levels. If you are registering below 20ppm nitrate you are good to go that long between water changes. If your nitrates are higher, then consider doing them more frequently.
5 actual gallons is close to a 17% water change when you factor in gravel etc.. 50 % is overkill but maybe good training if you ever need meds or have other problems. I do a 20% monthly and monitor my ammonia and use TDS as a barometer as when to change it. 30 long, fish only with live plants and Nerites