Large Or Small Water Changes (discussion)

everyday there's a dozen or more new posts about sick fish help.

everyone says poor water quality is the main cause for fish getting sick (besides new fish that get sick from the store). but some people do small water changes thinking that if I keep the water parameters 0, 0, <20 or <40 then i'm all good.

there's more to water changes than just ammonia, nitrites, and nitrates.


"Water changes do two things simultaneously. Most importantly they remove all the bad things that build up in the aquarium over time.

In these cases nitrate tests may show it is nice and low, but you have selected the one thing that you can test for and tricked yourself into thinking the water is better than it is. This is one reason why water changes are beneficial, even heavily planted tanks.

The other major function of water changes is to bring in good things that are used up over time. The end result of all the biological activity in an aquarium is acidification. This uses up the KH in the water. As the KH is used up the pH will decrease. Eventually the pH can crash. There are many other vital minerals and trace elements needed that are replenished with water changes."
Water Changes and Water Quality in Aquariums - Advanced Aquarium Concepts

How to avoid 'old tank syndrome'

my nitrates have never tested red (40ppm) its usually orange (can't really tell the difference between the shades of orange 10pmm and 20ppm). I still do weekly 50% water changes on both my tanks.

 

Makes sense! I love a good 50% water change once a month!

 

I sometimes equate water changes like this....

The atmosphere has 20.9% oxygen in it. If you're inside your house, at the office, or driving in your car, there is always 20.9% oxygen in to the air you breath.

Sometimes though, you have to open the windows of your home or car and let it "air out" and let some "fresh air in".

The fresh air still has 20.9% oxygen in it, but a nice exchange of fresh air is always good.

Same thing when we take our travel trailer camping in the Texas Hill Country. The air is a lot "fresher" up there compared to the humid air along the gulf coast.

Even if water parameters look spot on, it doesn't hurt to do an occasional large water change.

Only takes some extra time and effort.

 

Changing water is still highly under rated by most IMO..
It is the secret to long healthy fish life .
I love when people argue you don't need them or boast how long they can in between …
50% a week is a good number for a lightly stocked tank IMO.
I like 75-90% weekly or biweekly on my grow out tanks .
I don't like 'little small ones more often ' unless you are changing 25-33% daily you are just doing bad math ...

 

The secret of fast growth, health, and a long life. It’s the biggest single factor in all of it. Like the quote said, we only look at the one thing we test for. There’s much more going on. If the nitrates are low, do a water change any way and it’ll still perk up the fish and be beneficial for them. As long as parameters are similar it can do no harm.
I love the fresh air analogy. I also look at it this way, fish in a river get a 100% water change every second.

 

29G



water is drained into the 20 gallon blue tub.



55G






20G, need to get a wider pic next time, but its drained down to 3" of water.

 

It just so happens it was WC night on my 55 and one of my 5.5 which I am also a firm believer of at least 50%. A lot of times I do 60-70% on them and whoever said the fish are much more active is spot on. Why wouldn't they be they just got a nice "bath"

 

My favorite water change story is of a guy I knew years ago. He ran a small commercial angelfish operation in his basement, with ~20 breeding pairs. Their 25 gal tanks were bare but for sponge filters and he did weekly 90% changes (leaving water only 2" deep and the fish swimming sideways) with untreated tap water (temperature controlled, of course). People couldn't believe he'd shock his fish with untreated tap water, but he told of one time on change day, one pair looked like they were about to spawn, so he emptied their tank last and filled it first. By the time he had finished filling that row (5 tanks) those angels were spawning.

 

About a year ago, two separate fish forum water management gurus advised that if I kept a thick bed of gravel substrate and conducted at least one 50% WC each week, there would be no need to do gravel vacs. The theory being that the deep gravel bed becomes one big filter and the big WC removes much of the dissolved waste from the water column.
I took that advice, and have not gravel vac'd since. The gurus were right. The tank stays clear, the fish are colorful & healthy. The big surprise is the lack of bio gunk on the substrate. I guess the BB quickly breaks it down.

 

Yup, my answer to almost any problem or potential problem is a water change. Funny how folks with a few years of fish-keeping under their belts are almost unanimous in their devotion to the idea of changing water frequently and in large volumes.

Almost as funny, in a sad kind of way, is the flood of people who feel they have successfully mastered aquarium-keeping because they have had a tank running for a few months without any major issues. They know it all, they know that water doesn't need to be changed; all you have to do is throw enough money at the problem, dump enough miracle chemicals into the water, and hook up enough mysterious new filtration products and they know they will be guaranteed success.

They also make sure they school other newbies in this thinking. Fortunately, most of them quietly disappear soon afterwards. Hmmm...I wonder what happens to them?

I keep hearing about "old tank syndrome". Guess what? There's no such thing...the problem that some people have is "old water syndrome" and there's an easy way to avoid it. Just don't have your tank full of old water.

 

We are first and fore most keepers of water. Good water equals good fish. Now I push my water changes a little farther then most but I have access to around 6 thousand dollars of test equipment. Now my tanks are severely understocked so that's what makes it possible with out having sick fish. Now when I had my tanks stocked like you would expect I stuck with best practices. There is so much to water conditions that the simple master kit simply doesn't test for. Total dissolved solids. Total dissolved organics. Dissolved oxygen. Dissolve c02. What minerals as some are used up and others accumulate. The list goes on and on. So please just do your water changes. Every day I see multiple threads of sick bettas and I really don't know why. I currently have 19 of them and in 3 and half years I have had 0 issues with them. Ok I'm rambling.

 

Thank you for the advice. I'm new to fish keeping and read extensively about the hobby. Some advocate frequent and large water changes, others the opposite. I have tried to do weekly and every other week water changes between 20-80% and never seen a difference in Ammonia, Nitrite & Nitrate readings. They are always the same 0,0,5-10. But I will do weekly 50% water changes from now on.

 

There are fishkeepers who understand the importance of water changes and there are those who don't...yet.

We are first and fore most keepers of water. Good water equals good fish.

That should be on a Fishlore bumper sticker.

 

I have a feeling a lot of folks through the years have thought of me as the crazy fish lady that is constantly harping about water changing. In my humble opinion it is the number one way to keep fish healthy.

In some cases medication is necessary but fresh clean water prevents the need for medication in the first place in most cases.

I also think one large weekly water change does a lot more good than several smaller ones.

 

I use the old water for the outside plants- they love it

 

I subscribe to the large water change also! I will take Karen K2’s advice and use the water to water my garden!

 

So to start define large 50% or more???. I feel that large changes assuming done correctly ( PH, temperature and the likes are matched) are ok and would agree with you on keeping things in good order. That said, it is very tank dependent. Different fish may sense a large water change as a time to breed as an example. A big change in water could stress your fish. So it has to be done correctly.
So if large works for you great, in my case, I do 10-20 % weekly and maybe 4-6 times a year do a large 40%- 50%.
I think the important thing to remember is to do them, also, remember your filter, this should be kept up as well. When I do a large change I use the water to wash out my filter media.

 

I think the frequency of water changes depends on the ease of doing it. I change 80% of the water in my 55 gallon every morning because all I have to do is turn on and turn off the tap a couple of times to pull the water out and refill the tank with fresh water. And it takes about 15 minutes. I used to find it difficult and back breaking a long time back when I used siphons and buckets. But there is nothing like daily water changes if you want your fish to grow like weed and look really good.

 

I do my water changes every 5 days, usually 25% each time, check for damaging edges or rough patches that might hurt the fish and every 4th water change I service the cannister filter, increase the amount of water changed to 50%, rinse the media (change the media every 12 weeks)

After every water change I maintain the water quality with 5 to 7 Evolution Aqua Pure Aquarium balls and on media changes I add 10 balls to the canister with the new foam block so that water quality is not interupted or weakened

 

I do my water changes every 5 days, usually 25% each time, check for damaging edges or rough patches that might hurt the fish and every 4th water change I service the cannister filter, increase the amount of water changed to 50%, rinse the media (change the media every 12 weeks)

After every water change I maintain the water quality with 5 to 7 Evolution Aqua Pure Aquarium balls and on media changes I add 10 balls to the canister with the new foam block so that water quality is not interupted or weakened

Sounds good to me!

Here's my regime. Never lost a fish to disease. Never lost a fish young. I have been keeping fish 30 years +. I have kept everything from Endlers and Betta fish to Flowerhorns and Altum angels. From Clown fish to Gobies and their shrimp friends. I have also kept frogs.

At this time I have 2 large predator tanks. One with Flowerhorn and the other a jaguar, saum and JD.

25% water changes every other day. 2 FX 6 filters on each tank with PG simster glass media and sponges. Changing too much water at any one time can cause PH to fluctuate which does stress the fish more than anything else so beware!

 

If you like keeping fish like rats in a laboratory where you just need to keep them alive to observe them then by all means do what you are doing. The title should be changed to " one who manages to keep fish alive in a tank" . Another way of keeping fish is to think of the ecology first. Before I get to into it I will recommend a book by Louise Walstad, The Ecology of the planted aquarium. Good luck

 

My favorite water change story is of a guy I knew years ago. He ran a small commercial angelfish operation in his basement, with ~20 breeding pairs. Their 25 gal tanks were bare but for sponge filters and he did weekly 90% changes (leaving water only 2" deep and the fish swimming sideways) with untreated tap water (temperature controlled, of course). People couldn't believe he'd shock his fish with untreated tap water, but he told of one time on change day, one pair looked like they were about to spawn, so he emptied their tank last and filled it first. By the time he had finished filling that row (5 tanks) those angels were spawning.

I can't count the amount of times my fish have spawned during or immediately after a large WC. Minimum 50% weekly for me, as much is needed for each tank and 75-90% daily to every 3 days for growout.

I also had to do some 'emergency' water changes due to fish spawning hormones. An example would be a fish just laid eggs and they were eaten right away by tankmates. She might think the eggs are still there and keep protecting the area. They can be quite obsessed for days. A large water change resets everything.

 

Hello Redsev

I'm sure you did not intend your first Fishlore reply to come across as a little abrassive & self righteous.
Rest assured there are plenty of advanced Fishkeepers & Aquagardeners here to help the inexperienced along, but if professor Walstad wants to chime in her imput is very welcome.
I think its safe to say that the vast majority of hobbyist on this site only have the best interest of their fish in mind.

 

If you like keeping fish like rats in a laboratory where you just need to keep them alive to observe them then by all means do what you are doing. The title should be changed to " one who manages to keep fish alive in a tank" . Another way of keeping fish is to think of the ecology first. Before I get to into it I will recommend a book by Louise Walstad, The Ecology of the planted aquarium. Good luck

I'm pretty good at keeping fish alive in a tank. I will keep my feelings toward walstad to myself.

 

I have started using water from my indoor air conditioner unit. Dies anyone see an issue with this? Its the new type where the water drains intI a bucket

 

As long as it's clean water I don't see why there'd be a problem, I think it would just be pretty cold.

 

I have started using water from my indoor air conditioner unit. Dies anyone see an issue with this? Its the new type where the water drains intI a bucket

I have a bucket sitting below my window unit. I water my outdoor plants with it along with the water I pull from my tanks during water changes. Personally I wouldn't even consider using the water in my tanks.

The water in the bucket from your unit is condensation that has dripped off the coils in there. I don't think I would be at all comfortable using it for water changes. Most units pull warm air in and blow cooled air out. I would be concerned with what is in the air being pulled in and mixed in the water coming out..

 

Even though my little bio says "more than 10 years" I admit that it has not been ten years of success, it was ten-plus years of head scratching, with a very slow increase in success and longevity. When I started keeping saltwater eight years ago was when I started to get serious about water. Before that I was doing 30% once a month. Yes, I admit it. I did have moderate success, my tank was always clear (but we know that doesn't meant much), I had some fish that lived good long lives, but couldn't keep inverts alive other than MTS. Now I am up to 30% a week, on the big tank, and more if I have time. I'm still working out the kinks of keeping my first truly large, planned, planted freshwater tank. I always thought Freshwater was less work than salt, now I know it's just different work if you're doing it right.
The solution to pollution is dilution.

 

Water from your AC unit could have contaminants that would adversely effect your fish, I would be concerned about heavy metal. That said Its probably no worse then rain water which again I don’t endorse but people do it.

 

1st water change on my new 75g, using a 20 gallon blue tub and a 27 gallon storage container.



already took several 5 gallon buckets full of water out of the 27g storage container to water my plants/garden.

 

he used too much food color b/c his camera couldn't pick up the yellow color. but you get the idea.

 

But Skavatar, the fish store lady said doing large water changes often is a great way to kill my fish what should I do?

Being serious though, I definitely used to be one of the people that changed just a little water every week and called it good. Now I do 50% at least once a week and what do you know, I haven't had a single fish die with the exception of old age or just being doomed from the store. I'm probably with mattgirl on being a crazy fish guy because of how much I say to just change a lot of water. Best way to fix water quality? Big water change(s). Injured fish? Do lots of big water changes. Sick fish with literally anything but internal parasites? Just do some big water changes.

 

I too am in favor of a more than 50 % wc. It is like giving my fish there very own RedBull.

They are crazy for it!!!!!

 

weekly maintenance of Tidal 110 hob polyfil.

 

I wish I took a pic of my fluval206 I cleaned Sunday after about 3 months give or take it’s was let’s say pretty dark...

 

I'm a big water change kinda guy. Every week I do at least 75% or drain the water down to just above my canister filter intake (my Hydor is a pain to prime for some reason). I'm lucky enough to have very soft, non chlorinated well water. I dose Prime and Stress Guard while filling back up.

I usually clean the leaf litter out as well, rinse it, and let it out while I put my polisher and UV sterilizer in overnight. By the next day you can't even tell there's water in the tank that's how clear it is. I never vacuum the sand, I don't even have a vacuum.

My fish love it too, my blue acara breed every week and a half to two weeks, and my two female severum almost always lay eggs together on the water polisher.

 

Large water changes can be done but you have to make sure your new water is a very close match to the tank water. Ph and temperature are critical. GH and KH are important as well.
Understand that if the replaced water is not very close you are going to shock your fish with large changes in the chemistry and that is obviously not good for them.
I do not endorse large water changes unless absolutely necessary. Small weekly changes (15-25%), adequate filtration, no not over feeding. Should be all that is needed IMO