Why do we do water changes so religiously if we can remove the nitrates?

[Randy Holmes-Farley Verified Community Expert]

I was surprised it took 3 pages of crap to find someone to answer the op correctly. This is exactly what I was going to say. Nothing absorbing alk, cal, mag, and t elements as this is a "fish only". If you keep nitrates and phosphate in check, the less you need to water change.

I'm not trying to make a case for water changes in a FO (although I can if you want), but your statement blasting other folks is itself incorrect.

"Nothing absorbing alk, cal, mag, and t elements as this is a "fish only". "

He specifically says

" I also have chaeto "

That is a huge user of trace elements.

 

[the1320god]

I'm not trying to make a case for water changes in a FO (although I can if you want), but your statement blasting other folks is itself incorrect.

"Nothing absorbing alk, cal, mag, and t elements as this is a "fish only". "

He specifically says

" I also have chaeto "

That is a huge user of trace elements.

Not trying to blast others, but so much arguing over bs SMH. So do weekly water changes for ur chaeto ‍

 

[fish farmer]

I do water changes on my reef to removed some detritus, occasional tufts of algae and loose mushrooms/colt corals which are usually attached to tiny shell bits.

If I get a boost in trace elements, etc....sweet!

 

[Ippyroy]

I feel that no water changes can be a destination, but is a very bad idea for newbies. Part of the reason for doing them is to get into a solid maintenance schedule and keep up with it. It also helps you with keeping an eye on and watching your tank. Even in a tank with few to no water changes, there are still lots of issues that arise and the person maintaining that tank is able to spot it quickly and take the necessary steps to correct it.

The only people we ever hear from that don't do regular water changes are the people that are successful at it. The ones we rarely hear from are the ones who didn't succeed and are no longer in the hobby. I work with such a person. They killed numerous fish and corals. They are no longer in the hobby.

 

[Reefy Feller]

I am positive. I'm tired of seeing the same topic beaten to death. No one searches for previous threads on topics.

Not to interrupt, but I'm a newbie and am reading this thread because not all of us are experts and know what we're doing yet. I appreciate the information as I'll be getting a new tank with sump - never had a sump before so all new to me. Current tank has hang on skimmer and I kill myself with constant water changes. I'm currenlty reading and learning all I can so nice to not have to go back 5 years to find that one thread about water changes

 

[jaxteller007]

When I started out with a 75 tank (i guess "reef" although we only had one Duncan coral and a bunch of snails and hermits to go along with fish) I was doing water changes constantly and the tank always seemed to be "off". Part of that was trying to cheap my way into this instead of getting the right equipment at the start.
Back in late Jan of this year we made the move to a 180 tank. Made sure we had good lights, over sized skimmer, a sump with a fuge, and added a bio-pellet reactor. I could count on one hand the water changes I've done this year. Of the water changes I've done, one was the sump only to clean it out and replace the fuge mud, and 2 have been to try and thin out the copepod bloom we have going. Nitrates have stayed higher than most probably want (between 10-20) but rather than battle trying to lower them, we've just let the tank run. Our fish are all super active, healthy looking and plump, our Duncan coral has exploded in growth and we just added a pandora zoa and a kenya tree (i think) coral this week and they seem to be doing fine. So I don't see a need to worry about constant water changes now.
Our nitrates will probably always run a little high because we overfeed to keep all the tangs happy and not fighting each other.

 

[Tired]

Nitrates at 10-20 is very reasonable for many tanks. I wouldn't call that high.

 

[Timfish]

. . . Do I really need to be changing my water weekly? Especially if my nitrate levels are being kept so low between the low bioload, quality protein skimmer, and chaeto? . . .

What about heterotrpohic bacterial blooms that drop the oxygen levels caused by a build up of Dissolved Combined Neutral Sugars? Science is a long long way from understanding the various roles of Dissolved Organic Carbon and the nitrogen cycle is still being intensly studied too so it strikes me as a bit premature to think because nitrates can be controlled we can stop doing water changes. Personally I'm a big fan of weekly water changes but that's just my prefference. I am curious who's claiming weekly is a necessity? It seems to me it really is going to depend on the microbial processes in a particular system. With the right microbial processes water changes may not need to be large or frequent.

 

[ReefPig]

I run Triton “other methods”, so all of my major and minor elements are replenished within reason, I also don‘t have a nutrient issue, but...

I still do a water change every two weeks of roughly 25% using NSW.

I don’t like running carbon too often, I find it strips more good than bad, I tend to use it for emergencies.
We all stick our hands in the tank often and it’s impossible to remove all the oils and bacteria, ever wondered why zinc is high on ICP?

To me, water changes rebalance everything, and particularly using NSW, boosts the natural population of bacteria.

Since using NSW, my corals are happier, my ORP has increased, my glass is cleaner for longer, I have no visible cyano at all, problem algae has disappeared, my ICP results are better, my water is more clear, less bacteria problems and most important, my nutrients seem to largely be maintaining themselves, I do very little else, occasional small dose of carbon dosing (Tropic Marin)

 

[SMSREEF]

Not to interrupt, but I'm a newbie and am reading this thread because not all of us are experts and know what we're doing yet. I appreciate the information as I'll be getting a new tank with sump - never had a sump before so all new to me. Current tank has hang on skimmer and I kill myself with constant water changes. I'm currenlty reading and learning all I can so nice to not have to go back 5 years to find that one thread about water changes

Exactly why threads like this are kinda dangerous for people new to the hobby. Water changes are a great way to start. In my opinion, the only way to start unless you have an expert helping you with your new tank.

Can a beautiful tank be done without water changes, yes.

But if you have corals or macroalgea it will take a lot of testing and that gets expensive, trace elements to replace...more expensive. Chemicals to soak up phosphate... more expensive. Fish Only?... Then export media... more expensive.

Water changes are just easier and cheaper for smaller tanks that we tend to start with.

try sending tests in for ICP and dosing tank to keep certain elements stable... that’s crazy for most if us to even try.

I have a tank that I am trying to grow macroalgae in. I dose chetogrow to make sure I have enough elements. I do massive water changes on this tank because the chaeto may not use all the elements, or some of my macros may need other elements I am not providing.

I cannot see spending $30-40 On an ICP test waiting a week, then buying said elements that are low, or get result that says “do a water change”

IMO, get testing of Alk, Calcium, magnesium, nitrate and phosphate down, and dosing or exporting as needed. Then it may be time to attempt the no water changes with ICP testing and element replacement for corals and macroalgae.

Also a few tips for your back, a pump makes water changes easier so you don’t need to pick the bucket of fresh saltwater up to dump in your tank. You also could mark a line on your aquarium for how much you are changing each time and just run the tube out the window or the back door. Or get one of those python gadgets that hook up to the sink. All this could be bought for less than 2 ICP tests

 

[syrinx]

When we started keeping corals in the 70s, water changes were all we had to keep things under control. With modern systems and practices, this is not always needed-and if that is a goal it can be achieved. That being said, if the effort taken to avoid water changes was applied to a efficient changing system-then both methods could be compared on even footing. Myself it takes less time and effort to do weekly water changes than it would to keep up with the chemistry and systems needed to avoid them. My current home tank is pretty much a fishbowl- complete balance so no filters of any kind-or additives. This would not be possible without water changes. I have had other tanks, as well as client tanks with few to no change protocols. These tanks were often majestic reefs-and water changes would not have made them better. Finally with the breadth of my 40+ years of experience of marine aquariums and reefs-thousands of tanks-The mature tanks that have "strange" or difficult to solve problems usually are tanks that have minimal to few water changes.

 

[Greg Gdowski]

There are things that accumulate in your water that are not nitrates or phosphates which could be detrimental to overall health. You cannot directly measure them but many people acknowledge them and take measures to reduce them (carbon and other removal medias). As the article above shows, a diligent water change schedule will do a lot to mitigate that accumulation.

Even in a fish only tank, hormones and other waste compounds can accumulate which you do not want in your tank.

Interesting point. But are those accumulating at the same rates as the other issues (ie nitrates, phosphate accumulation or Alk, Ca, Mg depletion)? I don't know the answer -- just asking? A lot of us have gone a long time without significant water changes. What I mean by significant is 20%/wk. If I were to do 20%/wk and dose, I would in all likelihood be pulling out more beneficial nutrients than removing detrimental components.

 

[Scorpius]

Not to interrupt, but I'm a newbie and am reading this thread because not all of us are experts and know what we're doing yet. I appreciate the information as I'll be getting a new tank with sump - never had a sump before so all new to me. Current tank has hang on skimmer and I kill myself with constant water changes. I'm currenlty reading and learning all I can so nice to not have to go back 5 years to find that one thread about water changes

Another one who didn't use the search function. If you did you'd have seen a plethora of threads about water changes.
https://www.reef2reef.com/search/1410074/?q=water+changes&c[title_only]=1&o=relevance

 

[Sm51498]

Interesting point. But are those accumulating at the same rates as the other issues (ie nitrates, phosphate accumulation or Alk, Ca, Mg depletion)? I don't know the answer -- just asking? A lot of us have gone a long time without significant water changes. What I mean by significant is 20%/wk. If I were to do 20%/wk and dose, I would in all likelihood be pulling out more beneficial nutrients than removing detrimental components.

Probably depends on bio load, what species of corals or fish and their overall sensitivity. For most tanks under 100 gallons it's cheaper and easier to just change water and do estimative dosing than it is to ICP test, purchase additives and dose precisely all of the trace elements anyways. So it undermines the whole purpose of avoiding water changes.

 

[Perthegallon]

It seems that my fish and corals are happier when I do water changes have no idea why that is just is. There’s no reason to bash people who do water changes that ovb do it for a reason and I’m suspecting the maker of this thread has little experience in this hobby and just watched a lot of YouTube videos on the GREAT NO WATER CHANGE METHOD it’s completely bs it works great for some people but the majority of new tanks need water changes for the first year at least especially with dry rock but hey if no water changes work for you then go for it.

 

[Tired]

Well, yes, keeping the water clean is a good thing. Some tanks just keep the nutrients low via multiple removal methods, and as such don't need many water changes.

 

[Perthegallon]

Another one who didn't use the search function. If you did you'd have seen a plethora of threads about water changes.
https://www.reef2reef.com/search/1410074/?q=water+changes&c[title_only]=1&o=relevance

Maybe that’s what he did and started reading this thread....

 

[Greg Gdowski]

Probably depends on bio load, what species of corals or fish and their overall sensitivity. For most tanks under 100 gallons it's cheaper and easier to just change water and do estimative dosing than it is to ICP test, purchase additives and dose precisely all of the trace elements anyways. So it undermines the whole purpose of avoiding water changes.

I'm not sure I agree. I have only done 3 ICP tests in 3 years. You shouldn't need ICP tests to do dosing. I also think it is healthy for anyone to know what their tank is consuming -- regardless of whether they are dosing or doing water changes. I did water changes blindly for the first 8yrs of reefing ..... by following suggested guidelines. What I found was that being blind was not bliss. If you really want to understand how your tank is doing, you need to assess the rate of consumption. That really tells you what is going on with your tank. I consume about 1dkh/day in my tank. Dosing keeps that steady throughout the day. Changing water would work but I would be doing it daily. I can't do it weekly (ie. that would be an enormous change in alkalinity). Water changes only incrementally adjust your parameters. For example, if your tank drops to 7dkh and you change with new water (8dkH) -- that never brings you back to 8dkH unless you do a 100% change. So over time -- even with water changes -- you will either have do a huge water change or add chemicals to get back to square 1. Not sure it is easier. I would argue that you probably have to do more chemical tests to make sure you are not far from square 1. If your dosing amount is close to the rate of consumption -- your daily swings are actually remarkably small. But that is the key -- you have to dose with respect to the daily consumption. That is what makes it challenging for the novice.

 

[MnFish1]

I choose to do them - because - I decided to simplify my tank - no chaeto, no additions (except 2 part), no denigrators, etc etc. For me its carbon, skimmer and water changes. I dont do them every week - but I do about 35 percent every 2-3 weeks. Seems to keep my parameters in good range. I also do not need to be constantly 'testing' - I test all once/week, Ca, Mg and Nitrate every month. I find this to be much less expensive that constantly buying products, paying for more pumps for reactors, etc). I do have an apex - which I use as a temp backup - and pH check.

For me a water change is a 15 minute maintenance - pump out 40 gallons into the sink - put the pump in a 40 gallon brute can which has had salt mixing for 24 hours. The pump warms the water to the same temp as the tank. Done.

 

[MnFish1]

I'm not sure I agree. I have only done 3 ICP tests in 3 years. You shouldn't need ICP tests to do dosing. I also think it is healthy for anyone to know what their tank is consuming -- regardless of whether they are dosing or doing water changes. I did water changes blindly for the first 8yrs of reefing ..... by following suggested guidelines. What I found was that being blind was not bliss. If you really want to understand how your tank is doing, you need to assess the rate of consumption. That really tells you what is going on with your tank. I consume about 1dkh/day in my tank. Dosing keeps that steady throughout the day. Changing water would work but I would be doing it daily. I can't do it weekly (ie. that would be an enormous change in alkalinity). Water changes only incrementally adjust your parameters. For example, if your tank drops to 7dkh and you change with new water (8dkH) -- that never brings you back to 8dkH unless you do a 100% change. So over time -- even with water changes -- you will either have do a huge water change or add chemicals to get back to square 1. Not sure it is easier. I would argue that you probably have to do more chemical tests to make sure you are not far from square 1. If your dosing amount is close to the rate of consumption -- your daily swings are actually remarkably small. But that is the key -- you have to dose with respect to the daily consumption. That is what makes it challenging for the novice.

On the other hand - if you use a salt that matches the alkalinity in your tank - even doing a 100 percent water change shouldn't 'matter'. (As you said - you would of course need to dose to keep your alkalinity at a certain level). If we think about it - we basically do a '100 percent water change' - each time we add a new coral or fish (from the perspective of the new animal) - i.e. they are being exposed to your tank which is different than the one from which they came?