Are water regular water changes really necessary?

[EdSnyder]

I have had the same tank set up, 55 with a 15gal sump and 4 4ft VHO's, now for about 3-4 years. In the begining I had problems with nitrate and phosphate. About 6 months after I set up my tank I upgraded my skimmer from an aqua c remora pro to an Octo 200. Skimmer really works great, maybe too good. I have really gotten used to my tank and how much to feed and when to check water params etc.

My question is: if nitrate and phospate are low and Cal alk and mag are right where they need to be, and corals are growing good do I really need to keep changing water?

I hear a lot of people on RC claiming to be changing a lot of water on a regular basis. I used to. I am starting to wonder if I have been wasting a lot of time and money all these years.

The reason I bring this up is I have really been slacking on the water changes lately. I have been really busy. But it seems I have gotten some of my best growth when I do slack on the water changes. I end up doing a water change after while, because I feel like I have to. Then the growth slows for a while an then gradually starts up again. I am probably going on about 3 months or so without a wc and everything looks great and corals are growing better than ever. I have really had to keep up with cleaning the coraline off my pumps and glass lately which was never that big of a problem with this tank.

Im going to fight the urge to change water until I see the growth slow. Has anyone had similar experiences?

 

[Ranchero]

Changing your water is an important part of owning your system.
When waste accumulates in your aquarium quality of water changes too.
Water changes will remove waste from your water and brng back the valuable trace elements within the water.
Its also a great opportunity to clean your rock of any debree if you dont have alot of movement in your tank. A turkey baster or a soft tooth brush is a great way to remove anything.
Do more frequent small water changes rather then one big one. If you wait and do one big one this can cause fluctuations in your water perimiters that can cause your coral to get stressed.

 

[RVANANO]

This seems to be a regular debate on here. I do my water changes regularly (20 gallons every other week in my 120)

But lots of people have amazing tanks while only doing one change (if any) per year. I will continue to do my changes regularly but the other way seems to work just fine for many members as well.

 

[steelhead77]

I'd say: if it ain't broke, why fix it.

As long as you are getting the growth you expect and the water params are good, leave it alone. Are you dosing anything to keep up the trace elements?

AFAIK, the main reasons to do water changes are:
a) to export pollutants and
b) replace any trace elements used by the livestock.

I do about 40 gallons every 2 weeks on my 180. The main reason I do water changes is that I have a fairly large bio-load and this just helps to keep my nitrates from getting too high.

 

[me_reef_geek]

personally I test my water before adding or doing anything. water changes, mg, kh, ca,..... the list goes on

 

[reefgeezer]

The value of water changes really depends on how your tank operates and what kind of corals you keep. In general, soft corals require less water changes, SPS corals more.

IMO, the reasons for water change are export/dilution and manageing ion balance (trace elements). I'm not talking about calcium, magnesium, and alk. I'm talking about the lessor elements like iodine, strontium, iron, etc.

While I won't argue that some keep great tanks with practically no water changes, I would be careful as there seems to be a break point at which things happen quickly when nutrients are rising and trace elements are falling. I've been there. I slack on water changes for a while and everything seems to start doing better. BUT... About the time I start thinking I don't need to do water changes, something suddenly happens and my corals lose their color, bleach, or begin RTN. It then takes a boat load of large water changes to get everything back into shape.

 

[RVANANO]

Indeed^ IMO until someone shows me harms of regular changes, I will keep at it

 

[mc-cro]

I hate to admit it, but I went almost 2yrs without doing a water change, or little else for that matter.

I lost all my SPS, and about 90% of my LPS. but my clam, ricordias, and bubble algea loved it.

 

[aquamanpc24]

My reef tank is set to wet skim so I am replacing 5 gallons of salt water weekly with a gallon or so of ro water for top off. If his skimmer is set to wet skim or close to it, it may be the water changes he was putting off to begin with! lol I know that my tanks have close to "known perfect" specs but when I dont do my bi weekly 10 gallon water change on top of the 5 gallon weekly the corals and fish act less happy, so there is something to replenishing trace and unmeasurable elements. Remember things that are written in books are still being tested daily. We are learning things about corals husbandry day to day that rivals years worth of predated knowledge. Taxonomy of soft corals are being re written cause they were mislabeled. So I am a firm believer in water changes since it can not hurt, unless your replacement water is tainted that is

 

[EdSnyder]

I'd say: if it ain't broke, why fix it.

As long as you are getting the growth you expect and the water params are good, leave it alone. Are you dosing anything to keep up the trace elements?

I do about 40 gallons every 2 weeks on my 180. The main reason I do water changes is that I have a fairly large bio-load and this just helps to keep my nitrates from getting too high.

The only dosing I do is two part and mag. In my 55 I only have 3 small fish and crabs and snails so my bioload is on the low side. I was doing 14 gal changes in the past, every 2 weeks. If I can go 3 months without a wc, that is a big difference compared to 14 gal every other week.

personally I test my water before adding or doing anything. water changes, mg, kh, ca,..... the list goes on

I do too, that is one reason why I havent been changing water.

The value of water changes really depends on how your tank operates and what kind of corals you keep. In general, soft corals require less water changes, SPS corals more.

Very true, my sps seem to be the only prob. The softies and LPS seem to love this treatment but the growth has slowed on the sps a little.

 

[Alex T.]

I think the reason your tank is doing so well over the years is because of the husbandry, general maintenance and water changes that you've been keeping up with. For now anyway, I believe the added level of nutrients (however slight) are benefiting the corals but that over time they will accumulate and reach a point where you can't get things back in time. It's very appealing to not do water changes, but in essence it acts as a "re-centering" of a system. Ignoring them will eventually deplete something we can't test...and then the downward spiral ensues.

I like to think of it this way....a five gallon bucket of salt will last me roughly a month and a half in water changes. It's much cheaper to keep up with them than to have to replace all the corals in my tank. Plus, after the water clears from my weekly maintenance is when i see the best polyp extension and overall "vibrance" in all livestock.

 

[Sk8r]

LPS or softies will do better than, say, SPS without water changes. And fish kept with these corals will probably do better than, say, fish in a non-reef: it's my unsupported opinion that the corals improve the water a lot...mostly by helping the bacteria out and removing (eating) waste, while contributing their own waste---whatever that may be. I'm not a bioscientist, but I do notice greater stability in big-coral tanks I've had.

 

[robs.mark]

I think most reefkeepers will agree that regular wc's will promote a healthy longterm system. As others have said, trace elements that we dont even test for get replaced and nutrients exported. David Saxby said something along the lines of ' Its not fish and inhabitants we keep, its the water, if we keep that in check, then everything else will fall in line'. A statement i completely agree with.
When i scrape my glass weekly, i wc straight after, removing all debris in the process. I can certainly see a difference in my corals the following day..

 

[EdSnyder]

Regular water changes are what I have always done. I am not saying that they are not necessary. All I am questioning is how often do these water changes have to be? It seems that any time this comes up everyone starts preaching weekely or bi-weekly 10-20% water changes. I have always listened to this and done it out of habit. Now I am going to find out for myself. We all have different tanks, different sizes, different bioloads, different corals, different feeding habits, and different levels of filtration. I happen to have a very low bioload, light feeding habits, and strong skimming.
I am noticing good results with less water changes. I know this goes against most, but maybe some are wasting time and salt mix when you might get better results from being lazy.

 

[Mad_Reefer]

Every tank is different. I don't change water very often and I like the results I get. I shoot for 10-20% changed every 3-6 months.

 

[oscar.millan]

Only if you want your SPS to thrive and your fish to be healthy.

I think it depends, I've yet to see an SPS tank do well without water changes.

 

[brian15876]

i do 10 gal on a 95 every other week...have gone longer however this seems to work so i stick with it

 

[reefgeezer]

Just for discussion's sake, I'll make the assertion that a thriving SPS tank can be kept without regular water changes. The most recent nutrient control technique, carbon dosing, makes it almost impossible, but otherwise, if the tank is set up in certain ways, water changes can be greatly reduced. Calcium reactors can supply not only major elements but also the minor ones. Large fuges with Mangroves and other plants and algaes can increase export to the point that the export/dilution function of a water change is not needed. A DSB can increase export and provide minor elements. If all of these things are included in a well maintained system, water changes would be much less necessary and possibly unnescessary. I'm not advocating this system, but it is possible.

 

[Chihuahua6]

No method of export can remove everything therefor I am a strong believe in water changes. Experience over the years has also brought me to this conclusion.

 

[syrinx]

I believe in water changes- although I have seen plenty of fine tanks that seldom get one. I think they are a must for fish- less so for corals. It really depends on the tank and chemistry desired. On most of my tanks I do 10% to 20% every two weeks (bigger tanks get the lesser change%) But my living room tank gets a gallon or two changed daily- takes five minutes- its a system. I have seen several very nice sps tanks that do the gallon a day thing with great success as well. I have had nano tanks that i would do 100% change weekly, and other tanks that got a annual change- all were beautiful- but best practice is regular water changes.