How often should I do a water change?

[kengaroo]

I am reading from this forum that some people do a 10% water change every week and I heard from some friends that they change the water once a month. I want to know what should be the correct water change frequency and what percentage of the water should I change? If my ammonia and nitrite are 0 and nitrate is close to 0, do I need a water change even though the last time I changed my water was 10 days ago?

 

[ajroc31]

I will get beat up for it, and you don't need to listen to me. I think that the weekly water change are borderline barbaric. Ok maybe not that bad, why freak the fish out once a week for no reason. If your tanks requires water removal, every 7 days there is a problem there. I think that 10% water change once 4-6 weeks is sufficient. I mean we do spend thousands of dollars on the darn filters, skimmers, and so forth, just so every week we have to go do a water change. That's for the birds.

 

[usinkit]

i do 10% aweek. during the summer i get lazy and do 20% once a month.

 

[salty cheese]

IMO it depends on what you have in your tank, a FO setup with good water parameters needs it maybe once a month but if you have a tank full of corals and you want to replenish the minerals IMO once every 2 weeks is fine.
The decision should be based on YOUR water parameters and the needs of YOUR tank inhabitants. Again JMHO. ***)

 

[mudplayerx]

I do 5% every week. My corals don't like anything larger than that.

 

[sinner's girl]

depends on the tank. right now, I just have inverts. I do every 4-6 weeks. I've never done them weekly, ever.
So, if your water is good, then no, I wouldn't do one. But that's me. If you see nitrates start to raise, then do a water. Test weekly at least. Always test before adding a new creature and a few days later.
If you have cc, I would every 4-6 just to clean the cc, but if you have ls, and your levels are good, then no.

 

[mrmaroon]

I do 5% every weekend.

 

[diane4]

Golly, I do minimum 10% every week, without fail. And every other week 20%. Once every couple of months or so, I do a 30-50%.
I believe in weekly water changes. It stresses the fish and inhabitants for a whole 10-20 minutes, whoopee. But they thrive and glow after that. My clown fish love it, it usually causes them to spawn right after water change.
Even with the best of skimers and filtration, you need to remember that in the ocean, water is vast, there are no glass walls and circulation and replacement is constant. Not so in a tank.
But then again, maybe the people that do so little water change, like once a month - are the folks that believe in never feeding their inverts.
I have been doing big water changes 20-40% all the time in my saltwater tanks and have expereinced NO ILL EFFECTS, at all - just clean water, happy fish and verts, that enjoy their fresh meal every 2-3 days. Sounds pretty healthy to me. Would you want to live in a glass box and sit int he same bath water for a month.
Sorry, unless someone tells me why it is a bad idea, I can see no other evidence other than what I observe, healthy fish and healthy verts, clear tank and a few brief minutes of stress once a week. big deal. Don't you think that they deal with stress more often than once a week in the ocean.
WATER CHANGE, WATER CHANGE, WATER CHANGE. It is the most basic thing you can do for you fish and animals, very basic, like brushing your teeth. Thats my opinion.
I never have a problem with my water changes.

 

[thomas712]

kengaroo~
Here is the thing. Every tank is different, and every tank has different needs. All depends on if you have a light, medium or even heavy load of corals, the needs of the coralline, the inverts and so on and so on. So every ones water change is going to be different.
You are going to be the expert on your tank, so you will ultimately decide on what your system needs.
Why do a water change?
To keep things in balance, things like calcium, alkalinity, magnesium and other trace elements, that get used up daily by your system. As a nutrient export, this means removing old water that has dissolved organics like nitrates, phosphates and other things we just don't want in the tank water that build up on a daily basis. It opens the window and lets bad air out and lets good fresh air back into the system..so to speak. The water change basically covers our sins from overfeeding, neglect..etc..
Equipment has a lot to do with if you need a water change or not, and how large it should be.
If you have a protein skimmer to remove DOC's from the water column you may not have to do a water change so often. If you have some really good filtration that focuses on processing nitrates like a refugium with macroalgae then your DOC's might not build up so fast, thereby reducing the frequency of a water change, and so on and so on.
However one of things we are constantly testing for is the calcium/alkalinity/magnesium issue. We need to constantly dose or do water changes to replace those main ingredient's that are used by live rock, corals, shelled inverts.. and water changes are a great way to do that.
Think of it as breathing, we breath fresh air (oxygen) and breath out carbon dioxide (CO2), if the CO2 were to build up on our bodies then we would die. Same principle in our tanks, they occasionally need fresh air, so figure out what % water change is right for you and your tank.
That being said I do about a 20% change about every 2 weeks on my system (that's about 30 gallons). All depends on what my system is doing and if I need to do more frequent ones then I do.
Thomas

 

[murph]

I kind of relate this to the question; "how often should I flush my toilet"? Not trying to flame or embarrass anyone just trying to make a humours analogy.
In an enclosed system like an aquarium or a toilet for that matter waste build up! The only real way to remove these waste and replace depleted elements minerals etc. is to change out the water using a quality salt mix. Even if the bad thing are testing at low levels all the good things are slowly being used up by your inverts and need replacing.
Having a sump makes the water change all that more easy and causes virtually no disturbance to the main tank. In my case its a twenty gallon sump. Simple matter of shutting down the plumping for twenty minutes empty it out and replace with new, flick the switch and done in less than half hour. The fish never know the better other than breathing a little easier.
Smaller weekly changes run less of a risk of radically changing the water chemistry also.
I have a fuge but IMO water changes during my cycle and adhering to weekly water changes of 20 percent there after is the more likely reason that I have never had to battle any kind of nitrate problem.

 

[reefnut]

I currently do roughly 10% per week. As everyone has said, every tank is different. Doing weekly water changes is far from barbaric. In fact, just the opposite IMO...

 

[diane4]

Thomas, Murph and Reefnut. I couldn't agree with you more.
I do admit that I feed more than most because I like to. I love to offer foods and because I am a piggy about it, I have to make sure that I clean up waist and uneaten food.
And you folks really hit the nail on the head when you said, it really is going to vary from tank to tank and the tanks inhabitants and other factors. You are more correct than I was.
If another person had different animals and only fed tiny amounts or no target feeding because they have animals of that type or they believe in that, then my water change habbits might make their tank ill.
But, in my philosphy, I know I have a heavy hand with feeding. I like it. And the price I pay is cleaning the tank. And you know what, I have even cut back on my feeding volumes. I am learning, it's hard, but I am learning to go lighter on foods. I hate to admit it, but what people said was true, the BTA I have does so much better with a decent fresh meat meal twice a week or so, sometimes less.
But, I will always believe in water changes. I just see the reaction of my animals, they love it, it makes them feel good and it doesn't "flush" the toilet.
OK, folks you might cringe when I tell you this, but in my 5 fresh water tanks, I change their water every week, without fail and I drain the water to about an inch or so above the tops of their heads. They love the water change. And when I start to refill, 2 of my oscars swim through the water on the return and their colors get more vibrant. There is NO question - water changes in my house is as regular as filling a gas tank in a car, almost just as expensive..hehehhe, but a must.

 

[thomas712]

Originally Posted by diane4
OK, folks you might cringe when I tell you this, but in my 5 fresh water tanks, .
What? you mean there are other types of tanks other than marine tanks?

 

[fishmamma]

I would like to add another factor into the mix here, the age of your tank. If it is a new set-up IMO more frequent and larger changes are needed until the tank becomes more established.

 

[acrylic51]

water changes is far from barbaric. In fact, just the opposite IMO...
Every tank is different in deed, but still do 10% weekly