What happens if you never do a water change?

[Makubex]

Sailfin tang lasted about two weeks

 

[t5Nitro]

SPS predominant mixed reef, no water changes for somewhere between 8-12 months. Dose all for reef and phyto.

 

[MichaelReefer]

and your bioload is extremely small - and the stuff that has survived in your tank has adapted to the conditions. BTW - its a nice looking tank. There is no way to know - however - whether it would be better with water changes. I am curious - again not being critical - what are your numbers - nitrate, phosphate Ca Mg pH. and what kind of other export systems do you have?

PH: 8.2-8.5
Alk: 9.0
Phos: .10
No2: .05
Salinity: 1.026
Mag: 1327
Ca: 465

Clarisea Sk5000
Protein Skimmer
Just switched from a Refugium to a Algae Scrubber.

 

[X-37B]

I setup my 120 2.5 years ago with the idea of a no water change system. I followed Glenn Fongs method and ran his EZ but with a carx.
I went 18 months with good success.
Check my build thread as its documented.
I then did a 12g water change with no noticable difference seen.
I did another in a couple months with the same effect.
Around 2 years in I did one as the tank seemed off but no issues or parameters out of place.
After the WC my wife came home and ask what I did to the tank. The colors look brighter.
Anyway my system is now 150g total water since I brought on a 30g remote fuge.
I do 12gs a month and the tank just looks better, imo, after one.

I do the WC to remove any buildup of anything that may become toxic over time.

Even If I was to do no WC I still replace 300ml a day with fresh salt water as this is the amount of skim my skimmer produces daily.
Thats over a 1/2g a week.

 

[Acros]

Lots of us don't do water changes (I'm one of them).
I do dose alk and All For Reef, run a skimmer, UV and carbon. I have a mixed reef and everything looks and grows just fine.

How do you maintain the salinity? Skimmer takes out saltwater. Do you replenish salt water occasionally?

 

[Driceftw]

Fowlr is fairly easy to get by with no waterchanges as long as nutrients are under control since there will be no real need to dose/manage alk, cal, mg, and trace. Corals could be done with dosing but without even softies will suffer eventually. As far as the fish dying, it sounds disease related to me. They could have arrived healthy, but stress from shipping/transport etc. could easily bring out ick and other issues in some fish. Once something like ick or velvet is in your tank its there until you go fallow for 70-80 days.

 

[ZoWhat]

What happens if you never do a water change?​

Your corals never reach their full potential

I watch a LOT of various webcasts that have industry experts as guests. I yet to hear from any of their mouths state that a no WC method is an advantage. Most say no WCs leads to dull corals that don't grow out to their potential. There is no advantage to do a non WC system for the sake of coral animals. The only advantage is your own time efficiency.

 

[davidcalgary29]

I think that doing away with water changes is perfectly fine if your tank is mature, you have a viable nutrient export system, and you dose.

 

[MichaelReefer]

How do you maintain the salinity? Skimmer takes out saltwater. Do you replenish salt water occasionally?

I add salt to my ATO

 

[Acros]

I add salt to my ATO

Really! So your ATO water is at a very low salinity, and that keeps your display at 1.026 salinity.

 

[vetteguy53081]

What happens if you never do a water change but do replace a lot of that evaporated salt water wit fw, Considering nitrites ammonia and nitrates are good, no bioload except for cuc, because sometimes the soft corals of my friend do open up big then at times they "look smaller" and close up a bit... what could be happening?

I dont change water and this has been for several years. I do get a bit of evaporaton and ATO adds accordingly
I do however monitor my levels, cleans skimmer and filter socks regularly and add occasiolan liquid Bacteria - Bacter XLM

 

[Spare time]

What happens if you never do a water change but do replace a lot of that evaporated salt water wit fw, Considering nitrites ammonia and nitrates are good, no bioload except for cuc, because sometimes the soft corals of my friend do open up big then at times they "look smaller" and close up a bit... what could be happening?

I rarely do a water change (maybe 10 gallons a year on my 75 just for simple sump and overflow cleaning). If I did more, I would need to add nitrate and phosphate to the water every time.

 

[Dan_P]

What happens if you never do a water change but do replace a lot of that evaporated salt water wit fw, Considering nitrites ammonia and nitrates are good, no bioload except for cuc, because sometimes the soft corals of my friend do open up big then at times they "look smaller" and close up a bit... what could be happening?

I read through this entire post and wonder whether your question might be “is my friend‘s current bad luck with coral and fish a result of not performing water changes?”

 

[ecrumpler]

No water changes for me, I would have to does Nitrate and Phosphate if I did as well. Unlike a lot of tanks, my corals get super unhappy if I do a water change.

 

[reeftankdude]

I haven't done a water change in two years. I dose Alk, Calcium, Reef Plus, Trace Elements, magnesium.

Great looking tank. How do you remove fish, crab, and snail poop? What brand calcium, trace elements, and magnesium supplements are you using. Thanks

 

[MichaelReefer]

Great looking tank. How do you remove crab and snail poop? What brand calcium, trace elements, and magnesium supplements are you using. Thanks

I use Seachem for everything.

I dont generally. Occasionally I will syphon into a filter sock in the sump. Or will disconnect my powerhead and blow stuff around so it goes into the overflow.

 

[reeftankdude]

I use Seachem for everything.

I dont generally. Occasionally I will syphon into a filter sock in the sump. Or will disconnect my powerhead and blow stuff around so it goes into the overflow.

Great and thanks

 

[Duncan62]

Lots of us don't do water changes (I'm one of them).
I do dose alk and All For Reef, run a skimmer, UV and carbon. I have a mixed reef and everything looks and grows just fine.

Same

 

[jackiemon]

I add salt to my ATO

Good idea! How do you calculate how much salt to add ?

 

[Randy Holmes-Farley Verified Community Expert]

What happens if you never do a water change but do replace a lot of that evaporated salt water wit fw, Considering nitrites ammonia and nitrates are good, no bioload except for cuc, because sometimes the soft corals of my friend do open up big then at times they "look smaller" and close up a bit... what could be happening?

To not skew the composition of the water long term when doing zero water changes is going to be challenging.

Many of the processes we use effectively do change water (skimming, using a complete two part or Balling, etc.). Without any of those, the tank may be OK, but the water will drift more and more from the starting composition.