Tank cleaning

hansgruber7

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When you change 75% of your water, how do control your pH. Or do all your tanks just run at the pH from the tap, which means that most of the systems will be Alkaline. Then how do you keep acid loving fish or are they just something you don't consider.
If you do have varying parameters in your tanks for whatever reason or that vary from the tap water, I think it's better to do more frequent smaller changes. You could do two 30% changes a week rather than one 75%. I do one 25% a week on all four of my tanks and never had a problem since I've been doing that. The other factor is that I don't have extra heaters etc and don't have space or time to make sure I'm equalizing the temperature exactly every time. If you do a 75% change, you need to make sure the temperature matches or is at least pretty close. If you do a smaller change, you can ballpark the temperature and it's not as big a deal. Just my two cents.
 

Naughts

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Last water change I started the tank draining intending to do 50%. I then spilt a cup of coffee and got involved frantically trying to clean the carpet. Meanwhile my tank had drained down to 75-80%. It was no problem though because I change 50% weekly so my parameters match and I am used to gauging the temperature. I don't use a heater/ separate thermometer as I can easily and accurately tell temperature by touch, I am used to how much hot and cold water needs adding in any given season, and finally I double check the tank thermometer whilst refilling and it never varies more than 1 or 2 degrees which is fine for my community fish .
 

seangee

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If you do have varying parameters in your tanks for whatever reason or that vary from the tap water, I think it's better to do more frequent smaller changes. You could do two 30% changes a week rather than one 75%.
A week is not enough time for your tank parameters to change enough to cause a problem.

However if you change 60% of the water you are left with 40% of the original water (along with whatever bad stuff is in it).
If you do a 30% change followed immediately by another 30% change you are left with 49% of the original water (the arithmetic is fairly simple - feel free to check). IMO the amount of bad stuff you take out is more important than the total volume of water added.
 

itiwhetu

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No, it's not. I had a chance to spend a lot of time with a world renound ichthyologist many years ago when I was a member of the Detroit aquarium society. Dr. Jim Langhammer. He was one of the leading experts on live bearers, President of the ALA and curator of Belle Isle aquarium in Detroit. I'm going on a bit bit you can google him. Anyway, he had 65 tanks and an advanced water changing system, all automated. He changed 50% of all the water. I wish I could remember how often but it was more than once a week. He told me that water changes are the most important element in fish keeping. It keeps the water closest to a natural environment. Interestingly, his fish were the largest and healthiest I've ever seen in the hobby. He was responsible for many fish surfing in the hobby. Especially halbeaks and certain Goodeids. I've always followed his advice and rarely had an issue. In fact, he said that testing water etc, was hardly necessary if you do those large changes. His filtration was interesting too. I did the same (outside of large tanks) just a small homemade sponge filter.
Hope this helps. I was very fortunate.
With live bearers not so much of a problem as they like alkaline water, with Discus another story.
 

itiwhetu

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So your basis for doing 75% water changes is just in case a kid drops a whole lot of food in your tank. Nobody has told me how you keep Discus with 75% water changes off a town supply that is Alkaline.
 

Byron

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So your basis for doing 75% water changes is just in case a kid drops a whole lot of food in your tank. Nobody has told me how you keep Discus with 75% water changes off a town supply that is Alkaline.

These are two different issues, albeit connected for many aquarists. The water change is to improve the health of the fish, and there is enough evidence now proving that the more water changed the more often, the healthier the fish will be, all else being equal. There are discus breeders who change 90% of the water in fry grow-out tanks once, some twice, every single day. We know the fish develop faster and healthier, and the same applies to any fish. It is closer to nature.

As I noted in my article, and as others have mentioned, there is no detriment to larger water changes if the parameters between tank water and source water are reasonably the same. That is a given. If one decides to keep fish requiring water with substantially different parameters from the source water, one has to recognize the challenges this presents.
 

itiwhetu

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These are two different issues, albeit connected for many aquarists. The water change is to improve the health of the fish, and there is enough evidence now proving that the more water changed the more often, the healthier the fish will be, all else being equal. There are discus breeders who change 90% of the water in fry grow-out tanks once, some twice, every single day. We know the fish develop faster and healthier, and the same applies to any fish. It is closer to nature.

As I noted in my article, and as others have mentioned, there is no detriment to larger water changes if the parameters between tank water and source water are reasonably the same. That is a given. If one decides to keep fish requiring water with substantially different parameters from the source water, one has to recognize the challenges this presents.
Good reply @Byron. You have touched on my concern. To often on this forum site I see information given about 75% water changes, but no consideration for the requirements of the fish being kept. I know that Discus breeders change out 90% of their tanks, I know I have done that in a Quarantine facility. But they are unique situations which don't relate to the average aquarist who is using town supply, with hard Alkaline water. I feel very sorry for the Cardinal tetras being kept in a tank getting a 75% water change weekly off a town supply.
 

Colin_T

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So your basis for doing 75% water changes is just in case a kid drops a whole lot of food in your tank. Nobody has told me how you keep Discus with 75% water changes off a town supply that is Alkaline.
If you are keeping a specialist fish like discus, you make up the water in a holding tank and get the water chemistry and temperature similar before you use it. The same thing applies if you have soft water coming out of the tap and you keep Rift Lake cichlids or other hard water fishes. You prepare the water separately and use it when it is suitable.
 

AbbeysDad

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I believe that the objective of the routine periodic partial water change is to replace as much polluted water with fresh water as is necessary to maintain a high water quality. That being said, the volume and frequency required may vary greatly in different tanks (not even to mention plants and other factors). Consider a large planted tank with only a few small fish, vs. a 5g or 10g tank that's overstocked with no plants.
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Ideally if we were to mimic nature we would have flow through systems where fresh water is introduced constantly as polluted water is flushed away. Unfortunately, short of a well designed fish room or fish farm, it's just not practical in the average living room! So the next best thing is to replace the polluted water with enough volume and frequency to keep the water quality high... And that being said along with the simple logic that there's no such thing as too much fresh water, we can make the case that a larger volume of water more frequently is better than the alternative.
Then again, one might not entertain overkill - 50% daily could be great for many tanks, while 25% every other month would likely be poor. So we take the middle ground of 50% - 75% weekly as a fair average measure of good tank maintenance.
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Unfortunately there can be no absolute RULE as to the frequency/amount of partial water changes REQUIRED to maintain a high water quality - but again, we might agree that there's no such thing as too much fresh water.
Like @seangee and my friend @Byron, I rarely see sick or failing fish because the very best medicine is fresh clean water.
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Now the above is easy for those of us that have 'normal' water and present a potential problem for those with 'troubled' water that is either very soft or very hard. Now I'm of the school that believes that to a degree, fish can adapt to varying degrees of water chemistry so long as it's clean and fresh. But be that as it may, some waters like 'liquid rock' may need to be cut with RO or soft water, while very soft waters may need crushed coral or other mineral additives ESPECIALLY depending on the species the hobbyist wants to foster.
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This is a hobby (or maybe a calling) that really requires study and awareness which may be why the average Joe most often fails and the tank ends up in the garage, basement, or Craig's list. :-( ... But discussion forums like this just may help stop the madness. :)
 

seangee

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Now the above is easy for those of us that have 'normal' water and present a potential problem for those with 'troubled' water that is either very soft or very hard.
Here is an interesting observation for those that don't need to change their water parameters. I have very hard, basic water and choose to keep soft water fish. I manage this by using RO. IMO that is not changing the parameters because I use it all the time.

I have 3 tanks that use pure RO water. In theory each of these tanks should have the same pH as they all have inert substrate, similar levels of plants and wood and similarly stocked. Yet they have very different pH levels. One is consistently at 5.2 - 5.4, another at 5.8-6.0 and the third at 6.6-6.8. These all have a 75% weekly change using pure RO at pH 7. Normal test kits can't measure this low so I borrow a calibrated digital tester several times a year to check everything is still the same. The results are the same immediately before a water change and 12 hours after. (I have never tested immediately after but some of my fish are quite sensitive and have shown no problems).

Now I don't have a scientific explanation for this but with regular changes it appears that each system finds its own balance and returns there, other things being equal. But if I did not do regular changes on the low pH tank I expect over time that would drop to well below 4, in which case large emergency changes are likely to be fatal. As I said, no scientific explanation but I have seen others report similar observations.

What I do know is that after having tested weekly for years I now only test quarterly (actually when I remember - or if I suspect a problem) because, despite my meticulously kept logs, once I moved to larger water changes my water parameters never changed.
 

itiwhetu

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After reading the replies to this thread and others, I have decided to change my approach. Rather than say 25% that's it. I am now going to say change out as much water as you can without altering the water chemistry of the system. Under that approach I believe that each tank would get a water change specific to that tank. That would mean with observation if you had say 3 tanks, each tank would get a different volume of water removed and replaced each week, depending on the make up of each aquarium.
 

seangee

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After reading the replies to this thread and others, I have decided to change my approach. Rather than say 25% that's it. I am now going to say change out as much water as you can without altering the water chemistry of the system. Under that approach I believe that each tank would get a water change specific to that tank. That would mean with observation if you had say 3 tanks, each tank would get a different volume of water removed and replaced each week, depending on the make up of each aquarium.
That's fair. Mine is no rule. It is what I advise in the forum because so many posts ask "can I add more fish" and everyone wants to max out their stock levels and calls 3 anubias heavily planted.. In fairness mine are all quite well stocked - but unlike most I have minimal filtration, that's what plants are for.
 

Byron

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I have made the exact same observations as @seangee describes in post #55. In my case, my tap water is zero GH/KH and I do no buffering or re-mineralization other than the plant fertilizers which have in the past been a comprehensive liquid and substrate tabs, but now only the tabs. Over a period of years the pH has remained the same in each tank, but specific to each tank. My larger tanks tended to be in the low to mid 6 pH, while the smaller tanks were in the 5's or below 5. Same substrate, same type of plants, similar fish loads, same decor, weekly 60-70% water changes. Each tank established its unique biological system, and it stayed there.

Some members fail to realize that this is a scientific hobby. We create an artificial environment within a glass tank, but everything that occurs once we add fish is totally governed by the laws of nature/science, be they chemistry or biology. The aquarist can "interfere" to some extent, but this is always dangerous because this interference can have negative consequences as much as positive, and the science will prevail.
 

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