CichlidFish.com - Fish That Think.

I'm curious what the consensus is here for frequency of partial water changes? I imagine most of you will say "weekly". I do mine usually every eight (8) weeks or so (yes, I sed . I guess I've discovered through experience that I don't need them more often than that, but I'm super careful with amounts of food, how many fish in the aquarium, etc. So, how often do you do changes and what is the reason/science behind your decision?

--Mark:cool:

FTR (For the Record)

I do a once weekly, (sunday) gravel vacum, I remove about 15 gallons on average. Every second week, used to be weekly, I test the water for NO3. IF the NO3 is over 20ppm, then I remove additional water. I am carefull about food, mind you I have two young kids, who on occasion have been known to add exsesive amonts of food. I have two O's 8" and 5" not sure of the growth differnce, but thats how it is. They are in a 60 gallon tank, with two plecos. I let the NO3 decide on water changes now, but for the most part the gravel cleaning keeps it down.

My water change schedule is pretty much

- quaranteen tanks get one 30% a week until the fish are used to my water

- piranha tanks get 30% weekly - more when I have time
(300 gallon takes alot of time to change the water)

- normal tanks 3+ (up to 10) - 30% changes a week depending on my schedule

- Breeding tanks 4 or more 30%+ changes a week

- Stubborn breeders and discus 5 or more 50-80% changes or more a week
(discus pair also gets 1.5 times the tank volume "most days" via automatic dripper/changer)


- Fry/growouts -usually daily or twice daily 20-50% water changes.

- Discus grow outs get 60%+ daily water changes

+ whatever top offs maybe needed *

On average-sometimes a change is missed from lack of time,other times more frequent and larger changes when I have extra time.

what is the reason/science behind your decision?

- Faster growth and more frequent breeding :thumbsup:
- never heard of a place in the amazon, that the water doesn't change often or any world lake that is a stable set gallonage
- constant clean water =less chance for a problem
- more water changes,gives the ablity to feed more and keep the water clean,which goes back to the first reason

Hi.....i only do 25% water change every 2-3 weeks.but im running a big external and a powerful undergravel.and i only got 3 fish in my tank.......but as you said mark,when you know your fishkeeping then you tend to know what you can and cant get away with.
i would advise anyone new to the hobby to carry out weekly water changes.then you run minimal risk of problems.and to be completely honest i would say 90% of disease amongst fish aquaria is down to lack of water changes/bad tank husbandry.

Originally posted by Fuzzy
FTR (For the Record)

. I let the NO3 decide on water changes now, but for the most part the gravel cleaning keeps it down.

Enough said!!! I do my 80 everyweek like said depending on nitrate levels is up to how much i take out.. If it is 20ppm or more{never more if i can help it}I do 40% or 50% but i have a great bioload, tank is a bit overstocked untill 55 cycles..Still get into a routine of every week or two at least i say..