Water Change Amount

[ducatimikep]

I have searched & are unable to find
a "one size fits all" answer, so I will ask.
I have a tank ~6 months old. No issues.
All test give favorable results.
Here are the specs....
90g tank
15g sump
2 medium size tangs
1 BTA
1 Sally Lightfoot
2 Skunk Shrimp
A smaller than normal cleaning crew
a few small frags of montiporas.

Tests...
SG 1.025
pH 8.4
Nitrate 0
Nitrite 0
Ammonia 0

Is it necessary that I perform a 20gallon
water change per week?
Should I drop the amount or frequency?
Thanks,
Mikep

[BurntOutReefer]

I do 10% weekly. In your case, 10 gallons should be enough to replace essentials and to help dilute any nitrates......

IMO, its better to do small more frequent, then one large...in my perfect world, my tank would do a 1 gallon self water change daily.....but I'm too busy (lazy??) for that.

[Tswifty]

I do 15 gallons every 2 weeks on my 90g tank.

[Chago09]

my tank is over a year old and it has never seen a water change before. I have SPS,LPS and softies growing like weeds. I also have a stocking with a powder blue tang and anthias who are supposed to be sensitive although are alive and well for over a year. I think if you set up your tank correctly you never need a wc. A lot of old timers do it this way.

[Playa-1]

I do about 10 gallons every two weeks.

[Michael]

i do 10% weekly however ive let it go to 10% every 2 weeks lately and its all ok, randy suggests a 30% change now and again rather than less percentage more frequent changes, in saying that though he replaces 1% every day, just another look at it from a different angle

[ducatimikep]

Thanks for all of the responses.
I thought that 20 gallons per week
was a bit excessive.
I really do not mind a weekly water
change. I find it as "bonding" time
with my tank & fishes.
I think that I will tone it down to 10 gallons
(or % ??) weekly.

[tspors]

Ducat,
Here is the key to water changes. If you choose to do 10% weekly. Be consistant, do not vary from that. Your tank will adapt to what you do to it. Smaller changes 10% weekly are less invasive to the tank. However, if you want to vary from that, stay constant do not skip your routine. The tank adjusts to you, as long as stay consistant. There is no such thing as a bad dog, just bad owners.

[Mike31154]

Your bioload is fairly small for the size of your system. You could try stretching the timing a little longer or reduce the size of the WC. Keep an eye on your water parameters to see if you've gone too far with the reduction measures.

[reefworm]

depends on what you want to accomplish - nutrient transport, trace element replenishment, etc. But 10% - 15% a week or every other is not a bad figure, particularly, as mike points out, with your small bioload. I agree that consistency is important as well. There used to be an article out there by Craig Bingman on effect of water changes. Can anyone find it? I keep getting "file not found" messages.

[reefergeorge]

10 gallons a week on my 90, 120 total

[Brandon M]

I do a 15g change every 2 weeks on my 72g with 20g sump.

[goldenfamaliy]

7 gallons a week on a 75. And some times I do about a gallon to two a day when I feel frisky and want to chase the fish with the tube.

[crvz]

I do about 20 gallons on my 150 every 3 weeks. I'm kind of lazy about it, if I were diligent I'd do that consistently every other week.

[Chago09]

does anyone suggest why they make water changes??? I have never heard any good reason too. Everyone in this thread has said things from 10% weekly to 10% every three weeks and both are being successful.

FW I understand that nitrate is the final stage of the nitrogen process and can't be removed in FW besides a water change. My discus tanks I do about 25% every single day. I have a 150 gallon display and about 6x 40 gallon breeders and raising tanks. All get 25% a day. Thats because they too like SW animals need a next to zero nitrate.

In SW nitrate can be extracted through DSB, Live rock, Skimming etc. Thats the beauty about it. My tank has literally not had a water change in like 18 months. I top it up with RO water not RODI and my nitrogen cycle has been perfect all along. Nitrate is always undetectable. Now other trace elements are important as well calcium, alkalinity, magnessium etc. I have elected to dose these products. People do water changes and dose these anyways so I have elected to dose a little bit more since I don't get any help from Water changes.

This post was not to be rebellious, it was just to let the OP know that wc are not exactly going to be a requirement. Proper care, equipment and dosing will keep a tank running perfectly without any wc.

sorry for spelling mistakes LOL

[Randy Holmes-Farley]

I change 1% daily, automatically, and slowly.

does anyone suggest why they make water changes??? I have never heard any good reason too.

Never?

Here's some, some of which your monitoring and dosing do not impact (organics, metals, etc.):

Water Changes in Reef Aquaria
http://reefkeeping.com/issues/2005-10/rhf/index.php

from it:

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.

[reefergeorge]

Chago09.. Can you add a pic of your tank to go with what you say?
Then update your sig line..

[Chago09]

Randy, I hope you didn't take offence. I did say in my post I was not trying to be an a$$ it's just a method that I didn't invent. I started in the hobby recently although I spoke to a lot of old time guys who I met at local reef shops etc. I spoke to guys who had tanks set up for many many years and never gave it a water change, and he explained why.

Yes Randy I agree with what you said about the things that start to build up and some that get depleted. But organics you skim, metals should not be added in the first place if your water is RO, nitrate our systems can dispose of, and I use phosphate media for phosphate.

As for adding things back in yes I do that through chemicals. I dose all the chemicals my reef tank needs and I monitor them. Is my method the cheapest way?? I don't know maybe not.

All I was saying is that this is another method. I just don't like how some people on here assume that their method is right and everything else will fail if you don't follow their style exactly. I was just giving the OP another option if thats what he chooses.

As for a pic of my tank. I will take a pic tonight when I get home. Then will post tomorrow when I get back to work. You will surprised george. That a guy who didn't follow exactly what everyone on reefcentral says actually has a nice tank where the only thing I ever lost was watchman goby. knock on wood. My tank is not as full of coral as others although thats the way I like it. Whats important is I have a lot of signs of a healthy enviroment, like fat fish, beautiful corals, millions of pods, sponges growing like nuts and so much coraline that I am actually starting to hate it LOL

[Chago09]

ohhh and I never understood your pun about changing my sig line???

[Randy Holmes-Farley]

I'm certainly open to folks claiming that they believe they do not need water changes, or do not need as much. But the water will begin to deviate from the starting salt mix in clearly understood ways even with all of the supplementing and monitoring that typical hobbyists do. So the reasons are there, but we might disagree on the relative importance of many of them.

But organics you skim, metals should not be added in the first place if your water is RO, nitrate our systems can dispose of, and I use phosphate media for phosphate.

Some organics can be skimmed out, but some cannot. They simply are too hydrophilic to be skimmed or bound to carbon appreciably. that is why even folks that skim and use carbon can find their water less yellow when initiating ozone. That said,, the ozone doe snot remove those organics, it simply removes the color from them.

Metals mostly come from foods and as impurities in the additives that you use for calcium, alkalinity, and magnesium. There is a lot more to them than is listed on the label.

[Chago09]

ok Randy, those are valuable points and I'm glad you said that because I never knew. I appreciate the information, honestly.

So I have concluded this. I have not done a filter change in probably about 12-14 months. No ill effects. All corals are thriving, clams have grown substantially, fish have grown and been healthy(except powder blue had ich for about a week once although that went away and has never returned) coraline grows like mad, sponges everywhere etc.

Now if my tank has done so well in lets say for simplicity 365 days with no water changes. And like you said certain things can't be removed unless you do a water change, obvioulsy have not yet become in high enough volume to cause damage in my system. OK so I don't want them to ever get high enough obvioulsy I love my tank and its animals. So then one could assume the following: every year I do a 100% water change over a 4 week period doing 4 individual water changes of 25%. This would remove almost all of these organics, metals etc.

What I'm trying to do is take your advice but make sense out of it. My theory above is saying that yes a tank is obviously fine without wc for one year. So to be precautious change 100% of water over a period of a month of even two months, then your tank will be fine for another whole year.

Correct or no??

[Randy Holmes-Farley]

My theory above is saying that yes a tank is obviously fine without wc for one year. So to be precautious change 100% of water over a period of a month of even two months, then your tank will be fine for another whole year.

My tank was obviously fine without ozone for 10 years, as I never felt the need to use it and was very happy with the systems I had been using. I never noticed any yellowness, etc.

Then in the course of doing studies for an article, I tested ozone on it. It was easily seen to be better, both by eye and by measurement. Even my wife noticed it was clearer.

So the upshot is that things might be good or even great, but since there is no absolute way to "rate" an aquarium, it might be even better run another way.

[seapug]

Another thing to consider Chago09, is that your tank is still young. As time goes by, corals grow, chemistry shifts and the "no water change" philosophy that one worked fine for your tank may no longer keep up with Alkalinity depletion and nitrate accumulation. Do what works for you, but I'd be careful of shunning time tested maintenance and husbandry practices because of what some "old timers" at the LFS told you. You're not an old timer and those guys probably do a lot of other things to maintain their tanks that they haven't told you about. They've also probably experienced some major problems along the way that they've neglected to mention or completely forgotten about. If you do continue to trust this philosophy, be sure to test often to track your water quality.

As far as the 100% water change once/year goes, the problem you may face (or not notice outright) is the damage that can occur from the extended period that your livestock experiences degraded water quality. There's little doubt that you would probably have spectacular water quality after doing such a thing, but what about the other 300 days of the year?

[jubjub]

i do 5gallon once a week or so on my 75...only if i mix the salt to strong do i do more....sadly tank is so clean my clean up crew is starving...ha! anywho....

to be honest i think the real truth of what needs to be done is simply by monitoring the tank if you find your tank seems healthier when you do larger changes then maybe you should do larger changes. if your tank is healthy by doing 5-10gal changes then do that.

[Chago09]

Originally posted by seapug
Another thing to consider Chago09, is that your tank is still young. As time goes by, corals grow, chemistry shifts and the "no water change" philosophy that one worked fine for your tank may no longer keep up with Alkalinity depletion and nitrate accumulation. Do what works for you, but I'd be careful of shunning time tested maintenance and husbandry practices because of what some "old timers" at the LFS told you. You're not an old timer and those guys probably do a lot of other things to maintain their tanks that they haven't told you about. They've also probably experienced some major problems along the way that they've neglected to mention or completely forgotten about. If you do continue to trust this philosophy, be sure to test often to track your water quality.

As far as the 100% water change once/year goes, the problem you may face (or not notice outright) is the damage that can occur from the extended period that your livestock experiences degraded water quality. There's little doubt that you would probably have spectacular water quality after doing such a thing, but what about the other 300 days of the year?

well said, now what are some of these things that your saying could degrade my tank after they build up?? The nitrogen cycle has not beenan issue at all since all 3 stages have always been undetectable. Phosphate from time to time will rise but that simply tells me to change my phosphate media in the reactor. Salinity and temperature obvioulsy are not relevant to what were talking about. Alk and Calcium of course will depleat. I dose B-Ionic on a strict schedule thats followed religiously.

What other sort of things should I been looking for?? again I'm not being an *** I'm actually asking. I hate forums because tone and body language are not available so people misinterpret what I'm saying LOL