Water Change Question.

[robbrouse]

I hear all too often that my water so clear and it's been 6 months since I've done a water change. Or I change 10% one time a month.

Ok, my thoughts are weekly or every two week 15-20% water changes. I have been doing that on my fresh water tanks and I still have still have 90% of the fish I stocked it with 5 years ago. I know this is fresh and not salt, but I always thought we needed to add fresh new clean water for our fish regularly, am I wrong?
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[SarahSmile]

You are not wrong. Who is saying that they haven't done a water change in 6 months??

 

[robbrouse]

No one here. I have talked to people in pets store I have a buddy is San Diego, that tells me every 6 weeks. One of the owner of a LFS tells me his water is so pure twice a year water changes. IS it something that's even possible? Can you have a tank running so good every 6 week or 6 months?

 

[little_fish]

That works for some tank, but for the vast majority, no. I dont do very frequent WC on my tank, but for the first year, it was every weekend like clock work.

 

[JoeG]

new york steelo on you tube i think has never done a water change on his 90 gallon system

 

[robbrouse]

new york steelo on you tube i think has never done a water change on his 90 gallon system

Seems like I heard that as well. I just don't see how you can never or wait so long in between water chances.

 

[NanoReefer]

its been 4 months on my 37. i havent had coral growth as good as it now also.

 

[Bifferwine]

It can work -- for mature tanks that have been set up for a long time. You need some way to export nutrients, so a good skimmer and refugium, for example. You also need to test your parameters regularly and add additives constantly to compensate for what is being taken out of the water. This usually won't work for small tanks or young tanks. They just don't have the biodiversity needed to carry out all these processes on their own.

 

[Wet N Wild]

It can work -- for mature tanks that have been set up for a long time. You need some way to export nutrients, so a good skimmer and refugium, for example. You also need to test your parameters regularly and add additives constantly to compensate for what is being taken out of the water. This usually won't work for small tanks or young tanks. They just don't have the biodiversity needed to carry out all these processes on their own.

So for the cycling process and new tanks how often and how much should be changed out? 10% everyweek as long as things are looking ok?

 

[Bifferwine]

10% to 20% once a week or every other week is standard.

 

[parrotchute]

There are lots of answers out there. One issue to figure out is why you are doing a WC. If it is to export nutrients, your filtration probably isn't as adequate as it could be! With good filtration (scrubber, skimmer, live rock, biopellets, or whatever) water changes aren't necessary. However, a good water change will help maintain a balance of vital or important trace elements, such as calcium, magnesium, or iodine. This will be greatly influenced by your salt mix and is pretty important if you don't dose anything. A third reason for water changes is that it can potentially dilute harmful trace elements that build may build up, which is one of the suspects of "old tank syndrome".
So, sorry, no perfect answer, but those are some decent reasons why it's not a bad idea...I do it primarily to make slow adjustments to my salinity, since it drops over time due to skimming/salt creep.
Also, doing a bigger water change less often is more effective than many smaller water changes, since a smaller change will be taking out some relatively new water as well as old water. I.e., a 40% change once a month is way more effective than 4 10% changes.

 

[BL1]

More effective yes but, I wouldn't say way more effective.

Aquarists often think that many small changes are not as efficient as one big change since some of the water in all subsequent changes was already replaced by earlier changes. This is a correct assertion, but it is often overstressed. After changing 10% three times, only 10% of the first 10% change was changed the second time (1% of the total). So the difference is small. We can mathematically calculate the efficiency of such changes as follows. If we use our 30% example, then one 30% change removes 30% of the impurities, assuming an equal distribution of the impurity within the water. If we do six 5% changes, then the reduction in impurities = 1-(0.95)[SIZE=-1]6[/SIZE] = 26.5%. So it is less efficient (six 5% changes exactly equal 26.5% changed in one batch), but it is not radically less efficient. Going smaller still, the difference is even smaller. Doing 30 one percent changes removes 1-(0.99)[SIZE=-1]30[/SIZE] = 26.0% of the impurities.

 

[parrotchute]

More effective yes but, I wouldn't say way more effective.

Actually, after I posted it, I thought about editing and removing "way"...but laziness prevailed.

Basically every month you're replacing 34% of the water with weekly vs. 40% in one go. If my math is even close to being correct.

 

[beeguiles]

Like everyone sale said you can get away with very few water changes if your tank is mature and you have a lot of nutrient export and very good filtration. You really have to know what you are doing and be close to an expert to know if you will be able to run a system like new York steelo's.

 

[parrotchute]

+1 brittany.

The trick I use is to make water changes painless. I mix up the water in the basement, have a powerhead and heater in there. Then, I have pumps in my sump to pump water down to the drain and new water back in. 0 effort = good water changes.