Water changes are they really necessary?

[Captain Salad]

I stopped water changes about 5-6 months ago and only top up tanks, its a very established aquarium 400ltr and maybe some would say is overstocked by fish.

I do a water parms test every week and everything if fine so I just figured why keep changing water when params are fine?  So my question is are most people doing water changes without testing the water and just doing it anyway? TBH when I was doing weekly water changes the params weren't as good as when I stopped, go figure.  So do you think people should do water changes for the sake of it or only if params are out? Thoughts? Any problems for not doing water changes if params are fine?   

Edited September 30, 2021 by Captain Salad

[Guppysnail]

I don’t water change just for parameters.  I watch nitrates and doing very regular wc the rest of my Params stay close to source water. I do not alter source water. I feel there are many valuable micronutrients/minerals in fresh water that are depleted over time. And as the params change with time it is easier on the fish not to get readjusted after a length of time with no water change to then fresh source water.  All of this is just my gut feeling and supposition as I’m not the sciencey type but it has served me well for a lifetime. Healthy fish and plants 😁. In my mind It’s kind of like is taking a multivitamin necessary to survive..no..we get it from our food in a balanced diet but i take a multivitamin anyway just to make sure 🙃 so are water changes necessary probably not but but I do it anyway because it does not hurt but just might help. There are also stress and breeding hormones etc that plants don’t remove that build up so I feel removing them is a good thing. 

Edited September 30, 2021 by Guppysnail

[Captain Salad]

Thanks for the reply, when I say params I mean nitrates and the rest. My tap water has higher nitrates than my aquarium believe it or not 😞

Any thoughts on topping up tanks using water from dehumidifiers now and again? 

[Guppysnail]

On 9/30/2021 at 7:22 AM, Captain Salad said:

Thanks for the reply, when I say params I mean nitrates and the rest. My tap water has higher nitrates than my aquarium believe it or not 😞

Any thoughts on topping up tanks using water from dehumidifiers now and again? 

I have higher nitrates in my tap as well 20 ppm. So I keep my tanks at 20 nitrate I figure it’s at least consistent. I’ve seen talk on here of dehumidifiers. I would not because I can often see what grows in different areas of my dehumidifiers so don’t think it would be healthy. Even if I could not see it bacteria grows so quickly I would be afraid to including the minerals gh/kh would be minimal if any I would guess. 

[Captain Salad]

My taps 50 ppm 😞 Thanks for the reply and input, it is appreciated 🙂

[Guppysnail]

I have used natural jugs of spring water when my nitrates spike higher it word fine.  They still have nitrates but not as high. 

[anewbie]

There are two 'hidden' reason to do water changes. First solids will build up over time (use a tds meter); second fishes do release hormones and those also build up but this aspect depends a bit on the fishes you have. These are less commonly measured parameters; of course also nitrate builds up.

 

The reason soilds build up is they are in your tap and as water evaporate the solids are left behind so as you add more water it becomes more concentrated.

[Maggie]

There are many different opinions and practices on water changes on here. Some do it weekly and some never do it, and everywhere in between. Some like the process and do WC regardless of need, some to get rid of nitrates, some to prevent pH crashes, some are meticulous about regular vacuuming/cleaning, some just top off. Several with fish rooms have auto-water changers. I think there are some spirited past discussions about this subject on the forum. I do a WC every other week for the process and also to prevent pH crashes (soft water) but there are times where I tested and let it go an extra week or so.

[GameCzar]

I change water for parameters mostly, but some tanks (like our 5 gallon) are super stable, so it gets water changes to clean up poop, plant waste, etc.   Just keeping it tidy.    We also use that time to trim back plants or do any hardscape changes.

[Beccs410]

On 9/30/2021 at 6:33 AM, GameCzar said:

I change water for parameters mostly, but some tanks (like our 5 gallon) are super stable, so it gets water changes to clean up poop, plant waste, etc.   Just keeping it tidy.    We also use that time to trim back plants or do any hardscape changes.

Ditto for my tanks as well. I've done the "experiment" for determining how often one "should" change your water that Cory has posted on the Co-Op site, and I'm able to easily go a month or more between water changes. However, I like a tidy tank as much as possible, and I have lots of plants in all of my tanks, so I use a weekly, small (20%) water change as an opportunity for some trimming/grooming/adding new root tabs/switching in new IALs and alder cones. I'm a creature of habit, too, so I like the confidence weekly changes gives me. It's also a chance to really get a feel for what's going on in my tanks, how my plants look and how my fish are doing. I test my water weekly as well. I think that's more of a comfort level thing, though. And, I think that's what it all comes down to with water changes--what you're comfortable with and what works for your set ups!

[lefty o]

in most instances, the weekly water change just isnt needed.  smaller tanks need it much more frequently, larger tanks can go a very long time between water changes if the tank is well balanced and healthy.

[gardenman]

It's always an interesting question. Some say you need to replace trace elements that get used up. Eh, okay. Most quality fish food has an excess of trace elements in them though and whatever the fish don't use gets pooped out into the water to help replenish them. I don't do regular water changes largely because my tap water is so bad. (High ammonia, low pH, no KH.) I've had no issue with fish growth, reproduction, or any of the things you fear. I just top off the evaporation. If you have great tap water that comes out pristine and perfect for the fish you're keeping, by all means change it. If you have to manipulate your tap water to get it acceptable, you can probably get by just fine for most fish without changing it.

[Expectorating_Aubergine]

I don't change water or gravel vac. Pretty much all of my tanks just have airstones and plants. If I need heavy filtration, I just add terrestrial plants on top. I don't check water parameters anymore either. The only thing I add to the tanks is oak leaves.

leaves

[Mmiller2001]

I do water changes to target nutrient ppm and to keep consistent parameters. Also, organics come in several forms and the only way to remove them is via water changes. 

Unless you are testing every single element in your tank, it's impossible to know what's building up or depleted. Large 50% or greater water changes can remove those unknowns.

That said, I have very specific goals and I do what's necessary to achieve those goals. Therefore, water changes are 100% necessary.

Edited September 30, 2021 by Mmiller2001

[Atitagain]

When you only top off evaporation, aren’t you still doing a water change? Just at a much smaller scale maybe 3-5% as to I do about 20% every 2 weeks. For gravel vac, replacing nutrients, keeping parameters stable, ease of mind, and to keep tanks tidy. Sure natural conditions are not tidy, but my tanks are because that’s what I like. I also have a tank that is just beginning 2ish weeks old now that is darkwater, it will have litter, detritus, mulm and what not but I will still do 20% water changes.

I don’t think either method or plenty of other methods is right or wrong. Isn’t it really just how healthy your fish are. They can be healthy in a wide range of conditions.

edit: forgot to say I love this topic. Shows a wide range of how people maintain, which lead to a lot of learning.

Edited September 30, 2021 by Atitagain
Forgot

[Mmiller2001]

On 9/30/2021 at 9:11 AM, Atitagain said:

When you only top off evaporation, aren’t you still doing a water change? Just at a much smaller scale maybe 3-5% as to I do about 20% every 2 weeks. For gravel vac, replacing nutrients, keeping parameters stable, ease of mind, and to keep tanks tidy. Sure natural conditions are not tidy, but my tanks are because that’s what I like. I also have a tank that is just beginning 2ish weeks old now that is darkwater, it will have litter, detritus, mulm and what not but I will still do 20% water changes.

I don’t think either method or plenty of other methods is right or wrong. Isn’t it really just how healthy your fish are. They can be healthy in a wide range of conditions.

edit: forgot to say I love this topic. Shows a wide range of how people maintain, which lead to a lot of learning.

Just topping off is not a water change. Water evaporation leaves the tank at zero TDS, therefore the TDS in the tank rises. Nothing is removed. Adding back zero TDS water restores the tank back to the TDS it had before the evaporation. Therefore it's a neutral process to top off.

Edited September 30, 2021 by Mmiller2001

[Patrick_G]

I think the composition of ones tap water also factors into the equation. I have very soft water so I’m comfortable just topping up and watching basic water parameters to tell me when to do a change. Part of it is personal because while I love tinkering with the tanks I don’t love hauling hoses and buckets of water around. 

[Griznatch]

 I think it really boils down to a few key things...
The tank size, how heavily it is planted and stocked
The type of inhabitants you have in your tank.
Your source water.

Add in a lot of variables that don't often get mentioned in these discussions like,
does the tank have a lid, does it get direct sunlight, how often are your hand/arms in the water and do you make sure there aren't any lotion or chemicals on them...
 

You can see how just the things I brought up can make for such varied examples of how often and how much water changes are done if any at all...

[SWilson]

I wanted to bump the question on re-using water from dehumidifiers for water changes or top-offs.  I've been wondering this myself -- when I tested the water collected in my dehumidifier (just with a test strip), the parameters (in terms of ammonia nitrite nitrate) seemed fine, it was just really soft water.  Though I am not really sure since the AC test strips in general are showing much lower pH and KH for me compared to liquid tests.  I have tried using that water a little bit in a betta tank, and it seemed fine but I just got worried about my lack of testing and certainty that there wasn't anything potentially harmful in the dehumidifier water. 

For now, I've opted to just use the humidifier water to water my house plants.  But I live in California and being water efficient is a necessity.  Because of that, I've also been moving towards doing fewer water changes, its a great excuse to buy more plants.  🙂  Including pothos or other emersed plants that can help eat up the nutrients.  The main reason I do them now is if the hardness or pH seem way off in the tank, or if I'm servicing the filter.  Using Caribsea eco-complete substrate has also helped, in our experience tanks with that almost never read high nitrates no matter the stocking level or feeding.  

I have to admit it's been hard to fully commit to the no water changes method.  I don't feel confident that everything will be ok and I feel like a "bad" hobbyist for not doing them (I know how ridiculous that sounds).  Not to mention, hauling 5 gal buckets has been my gym membership for the last year+ and how else am I going to stay in shape. 😄 

[Jeff]

My tank prob doesn't need them with all the plants I have. 
 

However, I still do them weekly for a couple of reasons: it doesn't take a lot of time, and it's beneficial for the fish. 
 

A lot of things aren't necessary in this hobby. But, if you do the extra little things, it puts your tank, fish, and plants in the best possible situation to succeed and thrive. 
 

 

[lefty o]

On 9/30/2021 at 11:56 AM, SWilson said:

I wanted to bump the question on re-using water from dehumidifiers for water changes or top-offs.  I've been wondering this myself -- when I tested the water collected in my dehumidifier (just with a test strip), the parameters (in terms of ammonia nitrite nitrate) seemed fine, it was just really soft water.  Though I am not really sure since the AC test strips in general are showing much lower pH and KH for me compared to liquid tests.  I have tried using that water a little bit in a betta tank, and it seemed fine but I just got worried about my lack of testing and certainty that there wasn't anything potentially harmful in the dehumidifier water. 

For now, I've opted to just use the humidifier water to water my house plants.  But I live in California and being water efficient is a necessity.  Because of that, I've also been moving towards doing fewer water changes, its a great excuse to buy more plants.  🙂  Including pothos or other emersed plants that can help eat up the nutrients.  The main reason I do them now is if the hardness or pH seem way off in the tank, or if I'm servicing the filter.  Using Caribsea eco-complete substrate has also helped, in our experience tanks with that almost never read high nitrates no matter the stocking level or feeding.  

I have to admit it's been hard to fully commit to the no water changes method.  I don't feel confident that everything will be ok and I feel like a "bad" hobbyist for not doing them (I know how ridiculous that sounds).  Not to mention, hauling 5 gal buckets has been my gym membership for the last year+ and how else am I going to stay in shape. 😄 

probably someone who works in the hvac industry can give better info, but condensers in dehumidifiers, and ac units can grow bacteria and molds, and who knows what else.  the potential of what you cant see , and cant test for steers me away from using dehumidifier water. it has crossed my mind in the past, so those who ponder this question are not alone.

[Intuos]

I only generally do water top ups once a week due to evaporation from running without lids on my tanks, and a small water change one a month so I can use tank water to clean my filters. I test every week and never really get above 20ppm of nitrates due to planting levels.

It doesn't hurt to do them every week though, stability of your water parameters is more important IMO then anything else. As with most things in this hobby it's about asking lots of questions and then figuring out what works for you and your setup. 

[Streetwise]

I mostly run organic soil tanks, and I enjoy them because I can count on biology to keep things stable. I try to find a balance where top-offs are the only time that I have to think about water. I am very lucky with my water, and can top-off from my tap.

My other tanks have mulm that I squeezed out of sponges, with epiphytes and wood.

[Torrey]

On 9/30/2021 at 5:48 AM, Captain Salad said:

My taps 50 ppm 😞 Thanks for the reply and input, it is appreciated 🙂

Mine range between 40 ppm and 60 ppm, with accompanying swings in chloramine. I used to panic about it, but followed the science links that were posted in the aquarium science dot org site, and I have not been able to debunk anything he wrote yet, so I am no longer as anxious as I used to be. 

Most of my tanks are heavily planted and I honestly don't take out the majority of the dead leaves (snails handle them), or gravel vac the bottom (mulm benefits the plants), or do more than top off tanks during the winter (first frost to early April) because we live in the desert and water is life, and also due to health problems. 

In my experience, with very few exceptions, topping off every week, and watching plants, Inhabitants, and how the bubbles behave at the top of the tank, as well as water tests, my tanks are staying stable.

Only tank that is variable, is the turtle tank nitrates shoot up when the turtle chows on the plants🙄

There is new research happening regarding hormones in water, etc. and Guppysnail is right, we don't know every detail of the water cycle, minerals/salts and hormones, and what fish need.

And, there are people who strive for a balanced system that barely needs to be fed, and they have decent success. 

Also from my experience, be prepared for a bacterial bloom for 2 to 4 days after a 20% water change with nitrates coming out of the tap. Not all of my tanks have that problem, but my QT tank with the fewest plants looks like I poured a gallon of milk in after every water change. I add the Turtle sludge Destroyer, and it clears up in 24 hours... or I don't, and it takes 4 days.

That's been the biggest negative for straight from the tap water changes. 

Other option is a large planted tank / phytoremediation pond to preclean your water for you.

I run a phytoremediation porch pond April through October to treat the turtles water (can't use Prime, bad for turtle lungs), and buy water October through April.

I only do actual water changes when water tests say they are needed during the winter, and once a month April through October. 

 

[JettsPapa]

On 9/30/2021 at 5:22 PM, Intuos said:

I only generally do water top ups once a week due to evaporation from running without lids on my tanks, and a small water change one a month so I can use tank water to clean my filters. I test every week and never really get above 20ppm of nitrates due to planting levels.

It doesn't hurt to do them every week though, stability of your water parameters is more important IMO then anything else. As with most things in this hobby it's about asking lots of questions and then figuring out what works for you and your setup. 

I'm not trying to discourage you from doing the small water changes, but you can rinse your filter media in tap water (assuming it's from an established tank; I wouldn't do it with a new tank).