Why do a water change ?

M

Mandy11

Active Member
HI,
I am going to throw something out there and am really interested in people honest opinions.
I run a large system around the 1500lt (400g). I do a 250lt change every 3 weeks with Natural salt water.

I had a very experienced reefer come look at the tank and he asked what numbers I keep, I told him
my numbers, two of which are
Nitrates 0
Phos 0.03
He said "oh, so no water changes for you then "
I was suprised at this comment and asked what he meant, this was his answer. Just remember hes been reefing nearly 20yrs (very successfully, stunning tank)

Water changes every week were around and recommended before they had reactors and dosing products, it was the only way to keep parameters stable
. Now with GFO and phos removers, marine pure, seachem matrix for nitrate removal and tons of commercially available Alk /cal/mag for the big 3, plus trace elements in bottles that are created with huge laboratories over years of research, why do we water change.
We water change because everyone tells us too, not because it needed ?

I had never thought about this, we had just always done changes because we have always been told to right from when we started ?
His suggestion was that if your dosing, you only NEED to water change if you have excess nutrients ?

Do we waste a ton of money on salt that we don't need ?

I know with the 6 footer we ran on Red Sea Coral pro (very expensive here $150.00 for 3 water changes)_, we were slack and once went 17 weeks without a change and still had no excess nutrients.
The tank did not seem to suffer ?

Cant wait to hear peoples thoughts on this ?
Is he right ?
 
nanoreefing4fun

nanoreefing4fun

Well-Known Member
RS STAFF
The longer I am into the sw game, the more I realise there more than one way... glennf never does water changes and has one of the prettiest tank I have seen, PaulB I think does them fairly infrequently and it works for his tank.

I would say if someone wanted to give it a go... try it, it does work for some it seems, the only downside I see, is if it caused the tank to go downhill, it can be a chore getting it back in shape.

See what others think...

I would say though... the lack of regular water changes... has lead to many problems on tanks less than 100 gallons. Many don't dose & wc keep up what the corals use up. Stopping wc & starting to dose can lead to problems too...
 
M

Marty.h

Well-Known Member
I have not changed any water for over 6 weeks I have

0 Nitrates
0 phosphate

Salifert test kits

I don't intend on changing any water in the near future I keep SPS ,LPS and softies I do however dose A , B, C via a doser so this takes care of the main elements and trace elements.

If you can keep the levels where you want them and all corals ect look well then why change any water all you are doing is altering the chemistry and probably cause some minor spikes.
 
M

Mandy11

Active Member
it is so interesting to me, because I only started this hobby 2 yrs ago and the first bit of repeated and repeated and repeated advice I received was - Water change !!!!
Tank will fail, corals will die etc etc.
I cop a heap of crap now from people because I only change every 3 weeks, should be doing weekly, long term I will have issues ?
I still only change because i feel guilty not because my tank NEEDS it.
When did people start changing their minds on this subject ?
 
M

Marty.h

Well-Known Member
Mandy11 said:
it is so interesting to me, because I only started this hobby 2 yrs ago and the first bit of repeated and repeated and repeated advice I received was - Water change !!!!
Tank will fail, corals will die etc etc.
I cop a heap of crap now from people because I only change every 3 weeks, should be doing weekly, long term I will have issues ?
I still only change because i feel guilty not because my tank NEEDS it.
When did people start changing their minds on this subject ?
Click to expand...

You know your tank and stock better then anyone else if water checks out fine and all corals ect happy why mend what is not broken just because someone else changes water don't mean you have to also nothing to feel guilty about if your water still offers the perfect environment then why change it and basically waste money !
 
Dracko

Dracko

Well-Known Member
Lots of new innovations in the last 20 years. That said, it still will depend own you particular situation. Having a larger tank give you more room for comfort mainly because it is assumed that you have a greater sump and larger volume equipment. This greater capacity means slower changes. Those of us with smaller tanks (less than 100g) would be ill advised to forgo water changes. But I think it would be unwise to not be prepared to do a water change quickly if needed. Many things happen in the blink of an eye. Once had a child decide that he liked milk so much my fish would enjoy some too. If you don't feel you need to do regular water changes, with nutrient supplement, just remember to be ready for anything.
 
M

Manimore

Member
We did that had a mostly softie reef with only 4 fishes. No top so evap rate was 1 gallon per day. It ran great for 4 years until we moved and had to take it down. The first year we changed 20% /month then 1 x approx 20 gallon per year. We didn't dose anything but did have a well established fuge. We also fed only every 2 days. The only I'll effect was cyano about 1 month per year which was our indicator for a wc.


Sent from my iPhone using Tapatalk
 
M

Mandy11

Active Member
Very interesting. I love all the different points of view. @Dracko I am just like you. Not only do I have 2000lts of natural salt water at all times I also store 250lts of RODI and bucket of salt just in case. Trouble with such a large tank , if something does go pear shaped it requires huge changes to rectify. I just did my 3 weekly water change this morning ( 400ltr). Will test weekly ( normally do anyway) and see how it all goes. Will be very interesting to see how corals react.
 
D

DaveK

Well-Known Member
You need not be a fanatic about water changes and if your not having problems, doing one once a month or even less often is fine.

You do water changes for two reasons, to replace various trace elements as such that you can't easily test for, and to remove waste products you just can't filter out. It's like opening a window in your house once and awhile to air the place out.
 
Oxylebius

Oxylebius

Well-Known Member
Agree with Dave and Dracko.

What the inhabitants in the tank need are low nutrients and maintaining Ca, Alk, Mg, and all major and minor elements, and amino acids. These are maintained either by dosing and testing or by water changes.

Water changes are the easiest way for a newbie to maintain parameters.

It can be overwhelming when starting a tank for the first time and then having to also fiddle with lots of bottles of chemicals and setting up dosing pumps, etc. Not to mention more costs. It is much easier to do weekly 10% water changes until the tank matures and the hobbyist gets the hang of maintaining a tank properly. Then they can dig into the chemistry of the tank a little more.

One issue is that there isn't a test kit for every major and minor element. Therefore, it is sometimes hard to determine if there is something limiting in the water that is needed for one or more corals that you have. By doing water changes, you are essentially replacing anything that is low and needed.

If you are dosing and testing for Ca, Alk, MG, major and minor elements, as well as nitrate and phosphate, and if you have chemicals that are reducing toxins (that can build up w/o water changes) then you may want to change up your water changing routine. Either spread the water changes out over time or keep the same schedule but exchange less volume of water.

Ultimately it is up to you to decide what your tank needs to keep healthy fish and inverts.

It is very important to note that GlennF has an advanced computer system monitoring all parameters of his tank and he supplements what the tank needs on a weekly basis. Even though he is not constantly doing water changes, he is consistently monitoring and adding supplements.

Sometimes it take more work to consistently monitory, test, and dose supplements then it does to do a water change. The exception may be with very large tanks >200gallons.

This article is 10 years old, so some items may seem dated, but I believe you would be interested in reading it: http://reefkeeping.com/issues/2005-10/rhf/
 
Last edited:
nanoreefing4fun

nanoreefing4fun

Well-Known Member
RS STAFF
Mandy - Randy Holmes Farley is a highly respected Reef Chemist here in the States - good link ^ Sue

http://reefkeeping.com/authors/rhf.php

Randy Holmes-Farley has a BA in chemistry and biology from Cornell University (1982) and a PhD in chemistry from Harvard University (1986). He has 57 patents, numerous publications and several awards in a variety of chemical fields. In 1992 he helped start a pharmaceutical company (GelTex Pharmaceuticals). It was eventually bought by Genzyme where he now has the title of Vice President, Chemical Research. Randy is also the co-inventor of two commercial pharmaceuticals (Renagel and WelChol).

Here is his... Conclusion

Water changes are a good way to help control certain processes that serve to drive reef aquarium water away from its starting purity. Some things build up in certain situations (organics, certain metals, sodium, chloride, nitrate, phosphate, sulfate, etc.), and some things become depleted (calcium, magnesium, alkalinity, strontium, silica, etc.). Water changes can serve to help correct these imbalances, and in some cases may be the best way to deal with them. Water changes of 15-30% per month (whether carried out once a month, daily or continuously) have been shown in the graphs above to be useful in moderating the drift of these different seawater components from starting levels. For most reef aquaria, I recommend such changes as good aquarium husbandry. In general, the more the better, if carried out appropriately, and if the new salt water is of appropriate quality.

Calcium and alkalinity, being rapidly depleted in most reef aquaria, are not well controlled, or even significantly impacted by such small water changes. In order to maintain them with no other supplements, changes on the order of 30-50% PER DAY would be required. Nevertheless, that option may still be a good choice for very small aquaria, especially if the changes are slow and automatic.

Happy Reefing!
 
nanoreefing4fun

nanoreefing4fun

Well-Known Member
RS STAFF
One more good read...
http://www.advancedaquarist.com/2004/4/short

Particle extract...

There are few things in this hobby which are static or even thoroughly understood. The effects of regular water changes are no exception. I will illustrate for you exactly why I believe that water changes are an integral part of the regular maintenance on reef tanks and how much should be changed at once.

I constantly hear people say that they have never done a water change on their tanks. I have heard people say just the opposite; that they do very regular water changes. I have seen tanks that look great with both and tanks that look horrible with both - water changes are not a cure-all for everything nor anything specific. That being said, I will say that in my years of reefkeeping experience, almost all tanks that have regular schedules of water changes look the best.

and... one way to detailed article :winky:
http://www.reefkeeping.com/issues/2002-02/rs/feature/index.php
 
NickF

NickF

Well-Known Member
Wow, 30-50% water changes per day to maintain calc & alk levels, I had no idea it was that high. I change 25l per week and this works for me, I don't dose anything and I'm only testing my water every few weeks now because all my corals look happy. Guess it's because I've only got a small tank.
 
Dracko

Dracko

Well-Known Member
And none of this even touches on the fact that, with the smaller tank, dosing everything you need can be just as expensive as water changes. And in the long run may take less time than constantly testing and dosing.
 
You must log in or register to reply here.
Top