Big, weekly water changes. Good idea or not?

[Masha]

Good points, Delapool. And I suppose some fish will deal better with some things (ph change for example) than other fish.

But sorry for being dim, what is TDS? Total dissolved solids? Is there a way of measuring this?

The reason I'm asking about this is because I'd like to scale down a little on the amount of water I'm changing, especially if the amount I'm doing now (50%) is stressing the fish. But I don't want to compromise water quality, of course. At the moment, my nitrate levels are fairly low at the end of the week, about 12.5 if I remember correctly. But I'm having to over-feed a bit to make sure my bottom feeders get SOMETHING to eat and I'm a bit stressed about that.

Also I've got some emersed plants that are (hopefully) taking some of those nitrates out...

And I just don't trust my ability to tell if the fish are stressed. Guess I'm just going to have to try it and see what happens.

 

[Caliban07]

Now...the problem I have with the "you only need to do large changes if you overstock" thing is this: we all seem to have rather different ideas of what overstocked means. It's not that straightforward is it? I've seen people say:



"as long as nitrates stay below x"

"1 fish per gallon" (or whatever that rule is, can't remember now)

"what aqua advisor says"

"It just looks too crowded in there"

"well, they're not actually dying right now so they must be fine."



But it really depends on such a complicated balance between the type of fish, size of tank, surface area, amount of filtration, amount of feeding done etc, etc that "don't overstock" is just not very helpful advice.



I mean, it's not just about water quality, is it, it's also about swimming space, enough companions of the same kind of fish together, how aggressive a particular fish is...and even if you do focus only on water quality, what about the stuff our home tests cannot measure? I've seen people argue that just going by the nitrate levels is not enough, your tank might be full of all kinds of other chemical or hormonal substances that are harming your fish.



Which is kind of frustrating because you are left with "do large water changes just in case, who knows."

I don't think there is going to be the best one way to know if you are overstocked. A competent fish keeper ( I'm not having a go here) should be able to use all of those elements you have written and combine them with common sense to know if they are over stocked. I use my visual perception and nitrates to determine if I am under or over. I know I am understocked so if my nitrates were too high then I know I've been slacking on the changes.

I've said this many of time before during threads that in my opinion larger water changes are fine IF they are practiced RELIGIOUSLY weekly. As already stated, if your keeping regime remains the same then there is no reason that water parameters should alter enough to have an effect on the fish for example:

If I feed the same food and feeding pattern, add the same chemicals. Have the same maintenance and water change schedule every week the fish will naturally adapt to the regime and become less and less surprised by the shift in parameters because the shift is always the same. The water between points A and B is always chemically changing the same way every week. You just have to compensate that with fish growth.

It's when you alter from the norm it becomes a problem. You leave your changes for 2 weeks, you feed a new type of food or increase the amount you feed. Imagine you normally change 25% a week then decide to do 50% because you have left it for 2. That's not good for fish. Even if they appear ok but they could be going through some major physiological changes to their osmoregulatory system because of such a huge shift in TDS and TDS is just one of the factors involved although I believe it is the one that is most likely to cause fish deaths.

I believe fish can tolerate sporadic changes better than others but I just don't think it's worth the risk. If you feel like you need to change 50% of the water you should do it slowly.

Too many people believe that fish are tougher than they are but sporadic and drastic changes to any living creatures environment is going to have some kind of physiological effect.

Just my thoughts




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[Masha]

That makes sense, Caliban.

I do keep my aquarium keeping regimen really tight - always change water on a Sunday, every single week, always the same amount etc. The only change now has been feeding more as I think I killed some fish by underfeeding...I think we had this conversation before...

Although, I am trying something new now with aging the water for a few days, and heating it to exactly the correct temperature before pumping it in, so I'm hoping things will be even better now in terms of keeping things the same for the fish. Also makes the whole water change thing a bit easier to manage.

 

[Delapool]

That's it. Pretty cheap but I've yet to look into it and see if I want to get one.


http://stores.ebay.com.au/easylifeproduct/TDS-Meter-/_i.html?_fsub=818647016

 

[Masha]

That's it. Pretty cheap but I've yet to look into it and see if I want to get one.


easylifeproduct items - Get great deals on Waterproof Digital TDS Meter Water Tester 0-1999 ppm items on eBay Stores!

Ooh! That looks nice. I'd love to know if this is worth getting. Will look it up.

 

[Delapool]

Some other members may know I've been tempted but currently trying to stick to one parcel per month

Cheaper than a potassium test kit anyways!

 

[Masha]

Just reading through the thread again, and I realized something - I've still got a bit of a irrational response to the "overstocked" thing. Some time ago when I was even more of a newby than I am now, I asked for help on a forum (not this one) and I got totally piled on for having too many fish in my tank. People were really nasty about it too, it became a sort of all-out attack, although I did not respond to any of them.

They were right, the tank was overstocked at that time, but jeez, I wish they could have found a more diplomatic way of telling me. I just left that forum and never went back

 

[Pamiam]

I have a 55 gal tank and I do about 50% water change weekly. I have fish with large poop loads. I also fill it with a bucket so I can control the water temp.

My 20 gal. that houses bumblebee gobys only, I only do a 10-15 % water change, they don't need large water changes because they don't produce much waste.

It is just like my cats, I have 1 that is hyper and skinny and he gets 5 small meals a day, where as my other cats are fed once a day.

It all depends on the needs of the animal.

 

[PB_Smith]

I still hear my Mentor's favorite saying( Keep in mind he was a certified Ichthyologist, 12 years of training for his degree) , " If your water changes that much in a week's time that it's not safe for the fish to live in, you are either overstocked or under filtered. FIX IT! " I still follow that rule 50 years later. I just keep a nitrate test around for giggles. Never really need to use it

That sums it up rather well, IMHO.
If you need to do 50% WC's weekly to maintain parameters, than it's time to re-evaluate your set-up and make adjustments.

 

[BillD]

Regardless of how much filtration you have, the nitrates will rise weekly, unless the tank is very densely planted. So, even if the TDS stays the same, the water will have changed. Normally we alleviate this by changing water. We can determine how much and how frequently there needs to be partial water changes by testing for nitrates. Changing more than the minimum is better. The late Dr. Joanne Norton, who had a major impact on this hobby, advocated large water changes. She said, when speaking at a CAOAC convention, that her fish need to lie on their sides to stay wet during a water change. I have no qualms about doing that and have done it numerous times with no fish losses.
As to overstocking, it is difficult to define precisely. My opinion is that if you have a tank that you can't keep at a reasonable level of nitrates it is overstocked. However, if doing daily water changes prevents that is it still overstocked?
This is a photo of a tank in a zoo lab. The fish (Oreochromis esculatum, I believe) are part of a species preservation project and are 6" to 8" in length. Would you say this tank is overstocked? Clearly the fish are healthy and the water is sparkling, as the tank is maintained daily. Right next to it is another tank that is pretty much the same.

 

[Andy Sager]

Regardless of how much filtration you have, the nitrates will rise weekly, unless the tank is very densely planted. So, even if the TDS stays the same, the water will have changed. Normally we alleviate this by changing water. We can determine how much and how frequently there needs to be partial water changes by testing for nitrates. Changing more than the minimum is better. The late Dr. Joanne Norton, who had a major impact on this hobby, advocated large water changes. She said, when speaking at a CAOAC convention, that her fish need to lie on their sides to stay wet during a water change. I have no qualms about doing that and have done it numerous times with no fish losses.
As to overstocking, it is difficult to define precisely. My opinion is that if you have a tank that you can't keep at a reasonable level of nitrates it is overstocked. However, if doing daily water changes prevents that is it still overstocked?
This is a photo of a tank in a zoo lab. The fish (Oreochromis esculatum, I believe) are part of a species preservation project and are 6" to 8" in length. Would you say this tank is overstocked? Clearly the fish are healthy and the water is sparkling, as the tank is maintained daily. Right next to it is another tank that is pretty much the same.

My only question to this pic is: "Is this a tank on it's own or part of a larger system whereby the water volume is much greater than the size of the tank?"
No doubt many places overstock a container but they don;t overstock the system. If you looked at one of the warehouses I was part of building, you would have seen a tremendous amount of fish in 1200 gals of tank space but they were actually in 2500 gals of water. The difference was in the sumps so swimming space was the main criteria for the fish not water volume. Once again, you bring up the amount of space a fish uses in a tank, pond, stream, etc and you find that many fish we think are "cramped" are really right at home as their need for swimming space is not in their nature. So is overcrowding judged by space or water quality? My thoughts are water quality first. If I have enough fish in my tank ( assuming the swimming space has been addressed) that my water quality goes "South" in a week, I have too many fish in the tank. And that could happen with 2 or 3 fish in a tank BTW. It would just prove that the water volume of filter is too small for these fish.

I think we discussed this earlier in the thread but the main issue with changing large volumes of water only really applies when the water being used to replace the water being drained is of too drastic a difference in parameters. Keep those parameters the same and it's minimal to no difference to the fish. I just think it's really "overkill" to change that much water when the need is not present. If the need is present daily, then yes, it's still overcrowded. An aquarium in a closed system should be as close to an ecologically balanced system as possible. It should not be getting unbalanced daily. I doubt that happens in nature on a daily basis.

Regarding my comment about not changing PHs more than .2, this was the practice I was taught years ago and can't honestly remember if this was from my Mentor or my books. That being said however, it applies to immediate change not gradual change. For example, If I start at 7.0 and end at 8.0 during the day, the livestock will have had the chance to adapt to 7.2, 7.4, 7.6 & 7.8 along the way. If I start at 7.0 and immediately change the tank to 8.0, the livestock would not have had a chance to adapt and would suffer from this. We used to call this PH shock altho I believe it goes by other names today.

Hope this helps or better explains

 

[Caliban07]

Since nitrate counts towards the TDS the TDS will never stay the same. Unless we change 100% of the water TDS will always be rising. Albeit slowly. I do to know what concentrations start to affect fish or if they even do but there will come a point years down the line when the TDS in the system is so high that it will become so unstable when deciding to change large amounts of water. I believe this is called old tank syndrome? How fast TDS rises depends on a multitude of things.

If you have to make large adjustments to the fishes environment - just do it slowly.

It's only like any one of us attempting time climb Everest. You have to train your body to tolerate changes in temperature, pressure and oxygen to name a few.


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[meliboouk]

On all my tanks I've always done water changes at a third if the tank twice a week, the only time I've done more is if there is a problem in the tank,

My goldfish love water changes they love swimming in the incoming water,

I think it should be consistent, and as I do it twice a week, I'd rather do smaller water changes more often

Btw I have to do the bucket one over 12 buckets for them all in total that's just water going in roughly 12 coming out, and i still want more tanks lol


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[ScaryFatKidGT]

Now...the problem I have with the "you only need to do large changes if you overstock" thing is this: we all seem to have rather different ideas of what overstocked means. It's not that straightforward is it? I've seen people say:

"as long as nitrates stay below x"
"1 fish per gallon" (or whatever that rule is, can't remember now)
"what aqua advisor says"
"It just looks too crowded in there"
"well, they're not actually dying right now so they must be fine."

But it really depends on such a complicated balance between the type of fish, size of tank, surface area, amount of filtration, amount of feeding done etc, etc that "don't overstock" is just not very helpful advice.

I mean, it's not just about water quality, is it, it's also about swimming space, enough companions of the same kind of fish together, how aggressive a particular fish is...and even if you do focus only on water quality, what about the stuff our home tests cannot measure? I've seen people argue that just going by the nitrate levels is not enough, your tank might be full of all kinds of other chemical or hormonal substances that are harming your fish.

Which is kind of frustrating because you are left with "do large water changes just in case, who knows."

Yeah you could call one oscar and 10 neons in a 180g over stocked lol. I know big fish threw me off too, on AQ adviser you can have like 200 neons in a 180g but add a couple bala sharks or clown loaches and it says ur at like 70% stocking.

That makes sense, Caliban.

I do keep my aquarium keeping regimen really tight - always change water on a Sunday, every single week, always the same amount etc. The only change now has been feeding more as I think I killed some fish by underfeeding...I think we had this conversation before...

Although, I am trying something new now with aging the water for a few days, and heating it to exactly the correct temperature before pumping it in, so I'm hoping things will be even better now in terms of keeping things the same for the fish. Also makes the whole water change thing a bit easier to manage.

How large of tank/bucket do u have, I have 150g and am thinking off doing this, getting a garbage can or something.

That sums it up rather well, IMHO.
If you need to do 50% WC's weekly to maintain parameters, than it's time to re-evaluate your set-up and make adjustments.

Agree

Regardless of how much filtration you have, the nitrates will rise weekly, unless the tank is very densely planted. So, even if the TDS stays the same, the water will have changed. Normally we alleviate this by changing water. We can determine how much and how frequently there needs to be partial water changes by testing for nitrates. Changing more than the minimum is better. The late Dr. Joanne Norton, who had a major impact on this hobby, advocated large water changes. She said, when speaking at a CAOAC convention, that her fish need to lie on their sides to stay wet during a water change. I have no qualms about doing that and have done it numerous times with no fish losses.

See this is the crap I don't get, people think you need to do 90% water changes? What am I supose to do with my plants? and stuff, or my fish that like to hid in a log higher up, a water change of more than 40% just wouldn't work, I would need to turn off and re-prime all my filters, all my val's would have issues, I would pour holes in the substrate with the new water coming in....

As to overstocking, it is difficult to define precisely. My opinion is that if you have a tank that you can't keep at a reasonable level of nitrates it is overstocked. However, if doing daily water changes prevents that is it still overstocked?
This is a photo of a tank in a zoo lab. The fish (Oreochromis esculatum, I believe) are part of a species preservation project and are 6" to 8" in length. Would you say this tank is overstocked? Clearly the fish are healthy and the water is sparkling, as the tank is maintained daily. Right next to it is another tank that is pretty much the same.

I think that is a good question, I mean 40 clownloaches or something could probably all jam in a log or something in a river just fine because the river is bringing them new water, but I also think its a personal issue like in a store or museum you have staff and are always going to have the water changed, in your home unless you are willing to pay someone to do it when you can't, its a different story.

On all my tanks I've always done water changes at a third if the tank twice a week, the only time I've done more is if there is a problem in the tank,

My goldfish love water changes they love swimming in the incoming water,

I think it should be consistent, and as I do it twice a week, I'd rather do smaller water changes more often

Btw I have to do the bucket one over 12 buckets for them all in total that's just water going in roughly 12 coming out, and i still want more tanks lol


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I only do once a week but I'm about at that, 8-10 buckets..... I need a Python.

 

[Masha]

How large of tank/bucket do u have, I have 150g and am thinking off doing this, getting a garbage can or something.

I have a small tank - 90 litres, that's about 23 gallons. So my bucket is pretty small. About 9 gallons? I need to get a bigger one, but then I'll have to move things around in my lounge! It does make water changes a lot easier, as I can do the filling of the bucket, adding prime etc, on one day, and the actual water changes on another. Plus I'm completely sure that the temperature is right, (because I've got a heater in there) as opposed to when I attempted to mix it to the right temperature and never quite got it right.

 

[Luananeko]

Another thing to keep in mind beyond the whole bit of stocking levels, differences in water coming in vs going out, etc, is if the tank is planted... If it is, what's your fert routine? Sometimes you can be totally fine on stocking levels and matching water coming in vs going out, but you still need to do 50% weekly water changes to level out the ferts that are going into the tank each day and avoid algae. PPS Pro is one of the dosing regimens that do this, but there are several others too.

Basically, trying to oversimplify water change schedules down to a rule like the 1" of fish per gallon stocking rule is doomed to be as inadequate as that same rule. You really do need to take a look at all the factors and adjust for each tank's situation.

 

[gilpi]

Okay, I know this is a little bit of a hot topic, so I hope I'm not stirring up trouble by asking about it.

I see some conflicting advice about water changes. Now - granted - every tank is different, and somebody keeping discus is going to need to have a different water change regimen that somebody keeping a tougher fish like black widow tetras, for example.

But as a general rule - what do you think is the ideal water change regimen?
I see some people say 50% a week. Then I see other saying that will result in drastic changes in the water chemistry which is bad for the fish, and smaller, more frequent changes are better.

I can imagine that if you let your tank stand for a month or so and then suddenly do a 50% change, there would be a big difference between the tank water and the new water coming in. But if the changes are done weekly, is that really something that will stress fish?

And I mean "fish in general" if there is such a thing not special cases of more than usually sensitive fish. Is it this a "how long is a piece of string" kind of question that differs from tank to tank, or is there a rule of thumb that most of us can follow?

Too many factors involved to say exactly how much water should be changed.
One that doesn't get to much discussion is feeding. How much food one dumps in the tank also affects water, top that off with overstocking and your water will become a mess real fast.
I tend to feed more times a day than I should when it comes to smaller fish so therefore they get water changes more often, could be anywhere from once to three times a week around 20% to 80% volume depending how often I change it.
The so called "average" community tank and for those that want to go by the numbers, I would say 50% weekly sounds good as a general rule providing you keep and eye on your nitrates.
If your water comes in from the same source there should be no stress, it's more stressful for the fish to live in the same water with high nitrate levels for a month than it is to do a 50% water change weekly.

 

[PNWaquarist]

The so called "average" community tank, I would say 50% weekly sounds good as a general rule providing you keep and eye on your nitrates.

For the "average" community tank of 20 gallons or more that is not overstocked and whose fish do not have special needs, I'd say that 50% is more than necessary. There's nothing wrong with changing out half of your tank's water per week, but it's usually very easy to keep your nitrates in the 10-15 ppm range with 20-30% weekly changes. In some cases, it may be more convenient to do smaller water changes. In other cases, changing out a larger volume of water may not be any more of a burden.

Whichever route you choose, more often is unquestionably better than less often. I wouldn't wait two or three weeks to change the tank water, regardless of the percent volume of that change.

 

[Andy Sager]

Agreed, there is no "average" fish or fish tank. You can not make a general rule for all fish but you can make one for all particular types of fish. For example, For all tetras, how much water to change and how often? For all Livebearers, etc. etc. The big thing is your fish. If your fish look better after a water change, you didn't change it soon enough. If your fish look worse after the change, you changed too much.
I'll quote my mentor once again, " If your water goes bad in a week's time, you are either over feeding or under filtered." To that I will add that if you are not over feeding and not under filtered and your water goes bad in a week, you are OVERSTOCKED. Address that and your other problems should solve themselves.

 

[enrgizerbunny]

If you find a way to remove the nitrates you can refrain from water changes, but your water may still get dirty which would be corrected with a change. In general, I think if your going to do a water change, make it worth your time and change an amount that significantly stops your nitrates, or helps to remove excess nutrients, etc. While it's possible to have healthy fish with no water changes, it's not common or recommended.

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