Aquarium Water Changes: Why do you "change" a percent of your water?

[Tidal Gardens]

We have found that 10% weekly water changes work best for what we are doing.

We do this to maintain stability in both nutrients and replenish elements.

 

[Dani305]

About every 3 weeks, 20% or so.

 

[HawkeyeDJ]

I was doing 10% water changes faithfully in my 24g AIO cube for over a year. I was finding it difficult to maintain stability. My calcium, phosphate, and nitrates were bouncing all over the place. Then I stopped the wc and I'm just changing filter socks every 2-3 days and carbon/GFO about every 6-8 weeks. Now it appears my parameters are more stable. I know it sounds counter intuitive, but I'll continue to monitor weekly.

BTW, right now I am running primarily a softy and zoa reef. If things remain stable, in couple of months I may add some sps.

 

[Ef4life]

Because the water you removed looks like this when done properly

 

[Dburr1014]

On my 100 gallon system I do 1% Monday thru Friday. Skip the weekend so I don't have to hear the DOS pump. 20% monthly.
Used to do this manually but got lazy, so this is better than nothing.

 

[Susan Edwards]

I voted other. I don't do "regular" changes. My alk/ca/mg stay more stable if I do not do large changes. I will change out 3g in a day with auto water changes. That's 1.5%. So over a week I might do 5-6%. Then nothing for another few weeks. I probably do it to just get some fresh saltwater in or just because. I dose the big 3 and use the RS trace colors (ABCD) and others like chaeto grow which adds extra iron etc. If I medicate, like with reef flux, then I do a 20% change over a week doing the awc method. I like not having to bring in the brute and then pump out the old water. So much simpler.

Other maintenance I do weekly is to rake the sand bed. My flow is so good that not much settles except along the back a bit. After I rake and get whatever into the water column I dose "snow" (Calcium carbonate) as @SunnyX 's article promoted. That clears my water in 2 hrs and clogs my filter socks right up lol's. If I see a reason to do a big water change at once I will, but so far, I don't with my system

 

[bruno3047]

Over the years I’ve learned that no matter how hard I try, my sand bed will accumulate waste, and if left unchecked, will turn into a reservoir of poisonous detritus. So I’ve learned that In order for me to have a healthy, sustainable tank long-term, the detritus must be removed from my sandbed on a regular basis, and this also involves replacing the water removed in that process. Some people say detritus is inert. The stink from the water I remove says differently. To those who don’t clean their sandbeds and are still successful long-term, more power to you. To those who don’t have a sandbed, same.

 

[DeniseAndy]

Depends on my system.
My 6g I will do small water changes more often (weekly) and then one large one as needed (usually once every couple months or less). My 20g and 40g are the same system and they usually get one water change every two weeks of anywhere from 20% - 60%. Depends on what is going on in the tanks.

My main system gets water changes whenever I remember and feel like it. It is usually every two months or more. I am a bit lazy on this system. Then I will do a 20% or so at a time.

I do this to get rid of the detritus in the system and also to replenish system. Only the 210g has a calcium reactor, so the others need minerals and such replaced more often.

 

[shakacuz]

i chose other as i do not do water changes. if i were to do them, it would be for water clarity/stability.

 

[Ef4life]

We have found that 10% weekly water changes work best for what we are doing.

We do this to maintain stability in both nutrients and replenish elements.

Is that 10% number removal of water from selling frags and maintenance, or is that like a typical maintenance amount done weekly?

 

[Tidal Gardens]

Is that 10% number removal of water from selling frags and maintenance, or is that like a typical maintenance amount done weekly?

Typical maintenance, Every Wed is water change day and we change out 10% or more depending on what's going on with the system. If you pair that with the water getting shipped out, then you could say it's more like 13-15% every week.

 

[Reef and Dive]

I change every single week 15% to remove a ton of detritus and any excess substances. Just to remove detritus I would need that amount and pretty often more than that…

 

[reaper93]

Running tanks with HOB Filters, WC's are a must to keep nutrients in check

 

[Rick's Reviews]

Generally to clean up waste, my last wavemaker stumbled/stopped functioning fully and i replaced with a cheaper model with less turnover, noticeably different.. waste is just sitting around, 'buy cheap buy twice' new wavemaker on route

 

[vlangel]

I personally do 5% weekly water changes for all the reasons stated, that and I worked for a lfs that had aquarium accounts. I saw aquariums run 10+ years with no major problems when maintained by cleaning filters and doing consistent water changes.

In the beginning I thought that nutrient reduction was the primary objective ( and it is pretty important in a newly set up system). However as I maintained mature tanks, (my own included) I began to realize that replenishing the trace minerals and positive elements used up by the aquarium, is also very important.

Then I learned that the building up of tannins in the water can impede photosynthesis in coral so I decided the removal of that was important.

And of course keeping tabs on the salinity is important.

Could I tend to all these aspects without doing water changes? Absolutely, but doing a weekly water change covers all 4 areas with just the one action...a water change. To me that seems simpler, especially given that I made my water change procedure easy and without the drudgery.

 

[Novicereefer]

Let me start off by saying that this isn't a question to debate the validity of "water changes." You either believe that changing out your water is beneficial or you don't. Whether it's reducing nutrients, metering salinity, replenishing beneficial trace elements etc, you believe it helps or it doesn't. Today I want to hear from those that DO change out their water and as to why they do it. Let's do it!

What's the main reasoning/reasons behind why you, personally, change out a percent of your water?

How often are you changing out a percent of your water?

I change around 50% over the course of a week. 25% every 3ish days. I feed somewhat heavy to corals. Been experiencing growth so I take up the extra responsibility of doing more changes to keep my nitrates and phosphates in check. I could just feed less and change 25% a week but I'm enjoying the growth. I don't do 10% because I don't feel like it does anything

 

[salty_chimp]

15%-20% in my 3 tanks with skimmer (180, 80, 50)
roughly 35%-40% in my tank without a skimmer (11)

helps with my:
nutrient export (also, sucking out detritus)
keeping my water more clear (i mean, your water is yellow-tinted when you take water out)
micronutes
stability in my alk/cal/mag levels

 

[kevgib67]

12.5% weekly. Mainly for nutrient export and trace mineral replacement. Also i love how happy everything looks about an hour later, it is satisfying.

 

[Costareefer]

I voted other but main goal with WC is to vacuum out detritus

 

[MnFish1]

IMHO this is an an answered - and individual question - and should cease to be asked. NO offense - find something new.