Water Change Frequency

[waterdrop]

JustKia wrote:

BTT's comment about the essential minerals is one area I am interested in - and something I am looking into further - such as which are essential and which are beneficial, even if not essential, how much and what are the various sources of such (sorry, but I like the science bits).

I believe the main essential minerals you are asking about are:
Ca(Calcium), HCO3-(Bicarbonate),K(Potassium) and Mg(Magnesium)
called the "hardwater nutrients" by Diana Walstad
(p.114 Ecology of the Planted Aquarium, 1999,2003 2nd Edition)

I believe the posts by BTT and RDD outline the important bookends of this difficult topic, which has controversies which seem to still be alive and well also in the greater aquarist area outside TFF. With respect to the essential hardwater minerals, there are the two good aspects that: (1) pulling these in during a water change is good for the osmotic systems of the fish and (2)good for both the hardwater acclimated and softwater acclimated plants (per Chap. VII, same ref.). On the other hand, the water change gravel clean also removes DOC (Dissolved Organic Carbon) and other humic substances that can be very positive for plant growth. This last is one of the reasons Walstad advocates fewer water changes in the Walstad-style planted tanks. The other quite different consideration, which BTT mentions, is OTS, and its been mentioned numerous times on TFF that trace metals and organics that might eventually acclimate the fish to an environment quite different than what is eventually going to come out of the tap, is colorless, odorless, present in pristine tanks and not cheaply or easily measured. In other words, there are some good arguments in both directions on this topic and they are ongoing. At the recent plant conference I talked with many people who either have or follow some Walstad-style tanks and interestingly, the aspect they most often cited having a bit of trouble with, in theory, or that they don't follow is the infrequent water change. Most of them decided to change water more often. A lot of the discussion in our excellent thread here has been fish-oriented, and from that direction its pretty easy to lean to the frequent water change end of things, but for the mixed fish and plant aquarium and for the planted tank, the theories and discussion get decidedly more complicated I think.

WD
ps. I change 50 to 60% each weekend, but its not important to this discussion as I'm dealing with zero KH and low pH and haven't decided yet whether I want to move to crushed coral,

 

[Gooner]

OK I know at least a handful of people will jump and say they do x% water changes religiously every n days.
How often to you do your water changes?
How many do water changes based on stats?

The problem with this thread now is, that people who do less than weekly wc's are going to be put off posting by the aggressiveness of previous posts

I do a 30% change every two weeks. No problems so far (Had a few hiccups starting out but this forum soon pointed me in the right direction)
I don`t change on the basis of stats. Saying that I dont know what my stats are. I only test if I see any decline in my fishes health (Very Rare)

Edit....Being Honest

 

[Inchworm]

I really enjoy seeing a thread like this, where many different methods of doing the same thing are explored. It's not only enlightening, but I find it interesting to see the different perspectives the members have about their hobby.

I've gotten into the habit of doing my water changes on Sunday. Large or small, heavily or lightly stocked, once I hook up the Python and get started, all the tanks get a 1/3 to 1/2 water change. I've found that by sticking to this schedule I save myself the trouble of having to do regular water tests because the nitrates stay in the low end of the scale.

The only exception I usually make is to do extra, usually daily, water changes in the fry tank.

 

[aaronnorth]

routine - 50% weekly,
rescape - 50% daily for a minimum of 3days after
new setup - 50% every other day for a minimum of 2weeks

i dont test my water...

This last is one of the reasons Walstad advocates fewer water changes in the Walstad-style planted tanks.

also because our tap water is loaded with CO2 so these fluctautions are more likley to cause algae if you do a weekly waterchange.

EDIT: to the monority who think that a weekly water change is essential here is a tank that hasnt had a water change for several years:

(Tom Barr)

Ok it is planted which will help a lot to remove toxins etc but i am pretty sure you'll agree that it isnt necassary!

 

[three-fingers]

also because our tap water is loaded with CO2 so these fluctautions are more likley to cause algae if you do a weekly waterchange.

I wouldn't have thought so...after powering through the tap and splashing around loads, I would have thought the CO2 would have mainly gassed off, no?


My main heavily stocked low-tech planted tank gets water changes every 2-4 weeks, usually around 20%.
That's only because by that time the small bits of floss in the baskets are usually very dirty, and the filters intake get's clogged with bits of vallis.

I've had low-tech planted tanks go without water changes for 3 months before wit no problems at all (and that was at a time when I bothered to frequently test the water).

My high-tech planted tank gets 50% weekly.

My other small open top tanks really just get filters cleaned and topped up with RO/tap water depending long how long I left it.

 

[Jazzzz]

10gallon tanks every other week 50%
125L tank rarely but then its like the amazon and vastly understocked

 

[Jazzzz]

Anything less then 25-30% weekly is poor husbandry. If someone can't make time AT LEAST once a week to make sure their fish arent swimming in their own waste, then they have no business keeping fish imo.

Well surely plants will take care of polutants along with the filter and the solid stuff feeds the plants roots aftr the cories have turned it over

 

[matchstickman47]

There are too many good people here justifying themselves to you Personally I just think that you are opinionated.

Oh and continue....please..... as I won't be returning to this wooly thread

why is there a need to justify.?


i think this thread is abit bad

 

[glolite]

Anything less then 25-30% weekly is poor husbandry. If someone can't make time AT LEAST once a week to make sure their fish arent swimming in their own waste, then they have no business keeping fish imo.

What happens when you go on holiday? Perhaps you don't but when we take our 2 week holiday I just have someone check on the tanks to make sure they're running ok. They don't feed or water change and the tanks are crystal clear when we come home. I always test the stats on all my tanks after returning from vacations and they've been fine, saying that, the rest of the year I do 25% water changes on strict rotation and having 9 tanks that makes my routine w/c's every 9 days give or take. If there's fry that's an exception and their tanks have a w/c twice weekly of 50%

 

[JustKia]

i think this thread is abit bad

Why is it bad?
I asked for the honest answers of what people do regarding their water changes - and the vast majority have have done just that.
There's nothing bad about that.
I'm not about to go and tell anyone that they should stop using their system and use mine, like I said my other tank is vastly different and needs twice weekly changes. Nothing will ever work for everyone - types of fish, plants, other critters (inverts, snails, etc), filtration, lighting, volume, water used (bore, well, RO, etc), heating, feeding regime and many other things are all going to p lay a part in what works and doesn't for each individual.
And, fantastically, most of the people who have something bad/not great to say about another system (mine in this case) have been very constructive and stated why based on facts/research not personal opinion

In all I think it's a very interesting thread - after all not even those who do frequent changes do the same amount or go the same number of days - it varies from 3-4 to 8-9 days and from 10% to 50%+

 

[dave_oddballs]

i do 30 - 40% wc twice a week, not because someone or the web told me to do so. Just common sense in my case! Heavily stocked 240 L needs regular water changes! Some tanks don't, so people can only work off guidelines. No one can tell another exactly how to run and maintain their tank because how many people keep the exact size tank withe the exact equipment and exact volume and type of fish with same substrate and plants? Not many. In my experience people normally do better working from their own experience and learning from their own mistakes normally end up being more successful than someone who relies on the experience and advice of others throughout the duration of their hobby! This is my opinion so im not calling anyone (including myself) wrong or right

David

 

[glolite]

This is a good thread,very informative. Just out of interest, if you're doing regular water changes and your stats are stable with nil ammonia or nitrIte, how important is the nitrAte issue? I find this interesting because I've tested my tanks in the past and found them all to be around the same readings as my tap water. This subject has probably been discussed before but I've never been quite sure about the relevance of nitrAte to plants and fish. So is it good to have low Nitrate levels (I think yes)? Can you lower nitrAte levels in an aquarium below your natural tap water level and is there any need to? Are high nitrAte levels bad for fish but good for plants? Any information welcome.

 

[pippoodle]

i think this thread is abit bad

Why is it bad?
I asked for the honest answers of what people do regarding their water changes - and the vast majority have have done just that.
There's nothing bad about that.
I'm not about to go and tell anyone that they should stop using their system and use mine, like I said my other tank is vastly different and needs twice weekly changes. Nothing will ever work for everyone - types of fish, plants, other critters (inverts, snails, etc), filtration, lighting, volume, water used (bore, well, RO, etc), heating, feeding regime and many other things are all going to p lay a part in what works and doesn't for each individual.
And, fantastically, most of the people who have something bad/not great to say about another system (mine in this case) have been very constructive and stated why based on facts/research not personal opinion

In all I think it's a very interesting thread - after all not even those who do frequent changes do the same amount or go the same number of days - it varies from 3-4 to 8-9 days and from 10% to 50%+

I agree this thread has made interesting reading and i dont think it is bad at all and seeing as this is a forum and we are here to discuss these things then as long as any criticisms are constructive and no one gets abusive and personal then this is the sorts of things people want to know about
It's great that as fishkeepers we can all discuss what we do with our tanks - and what works for us

 

[rdd1952]

This is a good thread,very informative. Just out of interest, if you're doing regular water changes and your stats are stable with nil ammonia or nitrIte, how important is the nitrAte issue? I find this interesting because I've tested my tanks in the past and found them all to be around the same readings as my tap water. This subject has probably been discussed before but I've never been quite sure about the relevance of nitrAte to plants and fish. So is it good to have low Nitrate levels (I think yes)? Can you lower nitrAte levels in an aquarium below your natural tap water level and is there any need to? Are high nitrAte levels bad for fish but good for plants? Any information welcome.

Most people seem to think that nitrate should be kept under 40 to 80 ppm. Personally, on my API kit, once it gets much over 10 ppm, I can't tell one color from the other. Some in the UK have 40ppm or more in their tap water depending on the time of year. Tests have shown though that levels well over 100ppm have not harmed fish (delicate species not included). Obviously, there are other issues to be concerned about if its that high such as algae feeding off it.

If you have a lot of live plants, it's possible that the nitrate never will rise much as the plants use the ammonia before it is processed thus no nitrite or eventually nitrate. Is a low level good? Probably depends on plants you have. Some people have to add nitrate to their tanks to keep their plants healthy so in their case, low nitrates aren't too good as they have to buy it and add it. Getting it below tap water level is going to be difficult without some type nitrate filter but those become saturated in a relatively short period of time and have to be recharged. And as long as the higher levels from your tap water aren't causing other problems in your tank, there really isn't any reason to try to lower them below tap level.

 

[glolite]

Thanx rdd. So if you add plant fertilisers are you actually adding nitrate? I tried fertilisers but found they gave me an algae problem.