why do water changes?

[mcarroll]

enviroment that grows and maintains coral

All reef environments do that.

Whether you know it or not, you're probably already emulating one of the types, zones or locations described on Wikipedia here:

• Types
  • 2.1Fringing reef
  • 2.2Barrier reef
  • 2.3Platform reef
  • 2.4Atoll
  • 2.5Other reef types or variants
• 3Zones
• 4Locations

Corals on fringing reefs (for example) have massive water changes all the time.

Corals inside atolls (for another example) may get almost no water changes.

Water changes can do a lot.

Water changes are not necessary though.

 

[vetteguy53081]

 

[saltyhog]

Water changes are a tool. Whether and how often you do them depends on many things including types of corals kept, fish/bioload, amount and type of rock, sand bed depth, refugium+/-, skimmer size/effectiveness, reactors (GFO, biopellets or other carbon dosing, GAC)....and who knows what else.

 

[hart24601]

You hear a lot of talk about adding trace elements, water changes are nice because they help keep trace elements in range. Notice I didn't say adding. Its very possible trace element concentration can get too high via food inputs or supplements (either on purpose or as impurities). Water changes have the benefit of reducing the concentration if high, and adding it if low.

 

[Dumaurier7]

If using a skimmer then trace elements are not allowed to concentrate since they too will be pulled from the water.

 

[NY_Caveman]

One thing to consider is the size of the aquarium. In a small (nano) tank I would rely on regular water changes. Likely a nano does not have a sump, refugium or perhaps even a skimmer. Cheap, easy and effective.

On a very large system, water changes are not as cheap or easy to be as equally effective and the system is more likely to have several systems to augment processes such as nutrient removal and additives.

 

[jda]

Not all trace elements are able to be bound to organics to be removed from the skimmer - while it is technically correct that this does happen, it does not happen for enough of them. Many more of them can bind to aragonite which is Ok for a while, but can become an issue as time moves on and the aragonite gets saturated... this is one of the leading thoughts for old-tank-syndrome.

 

[hart24601]

If using a skimmer then trace elements are not allowed to concentrate since they too will be pulled from the water.

As JDA stated not all of them are removed with the skimmer and even for those which can be removed via skimming... how much is removed and what compounds? Exactly the same amounts you are feeding and dosing?

Waterchanges help reset these amounts to NSW (or whatever your salt mix is).

 

[BestMomEver]

I ask myself that question every time I do one! Not my favorite chore...

 

[Dumaurier7]

If you search the net (you tube I think ) you’ll see experiments where they’re growing corals in tanks with and without skimmers, with and without water changes for comparison. The “dirtiest”tank without the skimmer and no water changes had the biggest and healthiest corals.

 

[reef jacob]

So I I've only been doing no water changes for a couple reasons.
1. It allows me to keep everything as stable as possible because from each fresh batch of saltwater, there is always a small portion of variation which can cause stress to corals especially in regards to sps coral. Not doing water changes gets rid of that variation.
2. It allows me to be more lazy with the reef tank because hauling four 5 gallom buckets of saltwater sucks!
3. It allows the reef tank to be more natural and self sustaining. Say I ran out of salt I wouldn't have to worry because I would rely on the biological filtration instead.
4. BUDGET!!! Salt can get really expensive because i was having to buy a red Sea bucket of salt every 3-4 months which got spendy. Doing no water changes saves money because I don't have to buy salt.
Finally, I wouldn't recommend no water changes without having a lot of biilogibio filtration such as lots of well established live rock with sponges and stuff or marine pure blocks/spheres. Also VERY important to do carbon dosing or refugium. I do Red Sea NOPOX which is a organic carbon source. It rapidly increases your beneficial bacteria population which in turn reduces primarily nitrates and alittle phosphate.

To wrap this all up, no water changes requires a big skimmer, some type of organic carbon source or refugium and lots of surface area for beneficial bacteria to populate such as live rock and marine pure.

 

[reef jacob]

These two tanks are both ran on the same system which is a 40 gallon breeder diy sump with Redsea NOPOX for nitrate reduction and filter pad to get the large particulate organic waste out of the water, also a big reef octpoct skimmer.

 

[reef jacob]

These two tanks are both ran on the same system which is a 40 gallon breeder diy sump with Redsea NOPOX for nitrate reduction and filter pad to get the large particulate organic waste out of the water, also a big reef octpoct skimmer.

 

[hart24601]

I will say almost every single reef tank I see locally that has severe problems I ask how often do you do waterchanges, and the answer is almost always .... well I used to do them but I stopped ___ months ago. I then follow that up with how was the tank __ months ago? And more often than not the answer is along the lines of "much better".

Now this is probaly reflective of more a general disinterest of the tank than the impact of the waterchanges themselves - however it's worthwhile to point out. And they have NASTY sandbeds but that is a topic for different thread.

Generally tanks that are successful with forgoing water changes are people who have been in the hobby long enough or tank mature enough that they can experiment and keep an eye on the system while noting how long the last W/C has been. Threads like this also tend to highlight the few that have had good results doing it and not the many tanks that have been torn down that didn't get waterchanges. Again the lack of W/C doesn't mean that is why the systems failed, but it is a common trait.

I want to also point out that in all our systems we select for livestock that flourish in that particular setup. Ever have that one coral you just can't seem to keep despite many others doing great? We can only conclusively say that in a system we look at those specific corals will flourish. Not that this statement is directed solely at no waterchange folks, it's true in many aspects in this hobby.

 

[reef jacob]

I will say almost every single reef tank I see locally that has severe problems I ask how often do you do waterchanges, and the answer is almost always .... well I used to do them but I stopped ___ months ago. I then follow that up with how was the tank __ months ago? And more often than not the answer is along the lines of "much better".

Now this is probaly reflective of more a general disinterest of the tank than the impact of the waterchanges themselves - however it's worthwhile to point out. And they have NASTY sandbeds but that is a topic for different thread.

Generally tanks that are successful with forgoing water changes are people who have been in the hobby long enough or tank mature enough that they can experiment and keep an eye on the system while noting how long the last W/C has been. Threads like this also tend to highlight the few that have had good results doing it and not the many tanks that have been torn down that didn't get waterchanges. Again the lack of W/C doesn't mean that is why the systems failed, but it is a common trait.

I want to also point out that in all our systems we select for livestock that flourish in that particular setup. Ever have that one coral you just can't seem to keep despite many others doing great? We can only conclusively say that in a system we look at those specific corals will flourish. Not that this statement is directed solely at no waterchange folks, it's true in many aspects in this hobby.

That's very true but even not doing water changes, a sand bed can be nice and clean. Mine was pretty clean but I haven't had time to scrape the Coraline algae which makes it look kinda bad. Also keeping a conch snail and sand sifting starfish can make a sand bed look pretty great!

 

[hart24601]

That's very true but even not doing water changes, a sand bed can be nice and clean. Mine was pretty clean but I haven't had time to scrape the Coraline algae which makes it look kinda bad. Also keeping a conch snail and sand sifting starfish can make a sand bed look pretty great!

Oh yea, I didn't mean to imply it wasn't possible! System looks great!

 

[reef jacob]

Water changes are necessary for smaller tanks and definitely necessary for newer tanks but if you have a large tank that is very well established, and use very good filtration with red Sea NOPOX I would say it's a great method. That's why not alot of people do the Triton method because frankly it isn't for everyone.

 

[vetteguy53081]

All in all...... Many nutrients are absorbed and lost due to evaporation. Dosing helps restore essentials but the minor elements are also of value which are replenished during course of a water change

 

[reef jacob]

All in all...... Many nutrients are absorbed and lost due to evaporation. Dosing helps restore essentials but the minor elements are also of value which are replenished during course of a water change

I think if you have a calcium reactor that replenishes all the elements you want there isn't a need for water changes.

 

[vetteguy53081]

I think if you have a calcium reactor that replenishes all the elements you want there isn't a need for water changes.

Agreed but also consider it is not for everyone due to budget, space and startup requirements.