How much and how many water changes?

How many water changes and how often?


  • Total voters
    47
Yes, always. I ran out by accident once, but I made sure to leave my water out in 3 gallon bucks over night before adding (Of course I'm on town treated water too). I order on-line b/c I refuse to pay top $, thus the lapse, but now I buy the large size. :)
 
You can never do too many water changes. I do 50-60% water changes on my discus tank 2-3 times a week. The rest of the tanks get a 20-25% water change weekly and all of my tanks are sparkling.

Marinemom
 
I age my water as I have chlorine only. At least 24 hours. Of course I do keep some dehlorinator on hand for when I can't age enough water in one go.
 
Personally, I'm a big fan of minimum interference possible, maximum results possible.

This philosophy would drive a 10% water change every couple of weeks.

However, I'm reading in the forums more is better.

Can I get opinions on this?

Hehe...you have already created the most "interference" you possibly could in the first place...placing fish in a glass box. Remember, a neon in a thousand gallon tank would still be in no where near its natural environment it evolved in. With the exception of some localized fish that exist in small desert mud puddles, etc., fish in the wild are rarely in the same water for more than a moment...that is, lake, ocean, stream currents are always moving the water around the fish, or the fish is moving to other areas. The volumes of water in the wild are so ridiculously huge that we can't even come close to an appreciably measurable fraction with our tanks. However, the concentration of waste matter in a day in our tanks is ridiculously huge compared to carrying capacity in the wild. I go with 50% weekly minimum. I have NEVER had any ill affects from a large water change...quite the opposite...healthier fish, better appetites, better colors, more spawns....get the waste out and keep the fresh water coming in!
 
Whatever it takes to keep the nitrate level where you want it.

I do a 50% WC once a week. There are Discus breeders that do 50-100% a day on their grow-out tanks.

It's interesting to look at the math in this post: http://www.simplydiscus.com/library/water_chemistry/general/wc_formula.shtml

A 10% WC a week, done a little every day, means the fish are living in water with 75 days worth of waste in it!

10% done once a week all at once would mean the water stabilizes at a level of ~56 days worth of waste; 10% every two weeks would mean the water stabilizes a a level of ~125 days worth of waste, assuming I did the math correctly.
 
The math - nothing but the math


The math is not overly complicated - but to save everyone the trouble

For WEEKLY water changes, assuming steady waste production (and no plants:) )
the maximum level of waste stabilizes at (change week to day above and below - all remains same)
10 % => 10 WEEKS worth of waste
25% => 4 WEEKS worth of waste
33% => 3 WEEKS worth of waste
50% => 2 WEEKS worth of waste

Right after the water change you are going to be 1 weeks waste cleaner than the above table? Each day you will go up by 1 days waste, till you reach the highest level just before the PWC.
Cool!
 
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