Water Changes - Continuous or None?!?

[Count Krunk]

Hello all,

I would like to introduce a methodology from reef keeping.

We will start with continuous water changes.

In reefing it has become popular to change a % of your water. Every day. Via dosing pumps. It happens automatically and is automated. Usually. Then the reefer does large scale water changes 3-6 times a year. Or less. This is done to gain the positives of water changes without the hassle. And to gain the positives every single day. The positives mainly being element rich water going into the tank.

The other method is no or as few as possible water changes. This is to reduce cost (salt) and effort (water changes). The keys being dosing and proper nutrient export to maintain good element levels.

What is (are) the main point(s) of doing wc in planted tanks? Reduce waste levels? Has anyone tried to do as few wc as possible? And rely on other methods to maintain proper levels?

 

[Pepere]

Early on I watched videos arguing that you do water changes to reduce nitrate levels.

I had a heavily planted tank with a fair amount of floating plants.
apAs such I had to dose fertilizer to maintain nitrate levels so I figured I didnt need to do water changes.

I also struggled with Algae continuously.

I now do 50% water changes weekly along with using pressure co2 and good flow with a canister filter And plant husbandry techniques that all play a part in minimizing algae growth.

I cant imagine not doing at least 30% water changes on a weekly basis myself. Water changes give you the opportunity to vacuum out debris, detritus, removes plant waste organics, reset fertilization levels and refresh ferts, remove growth limiting hormones, allelochemicals, prevent minerals from concentrating over just doing top offs. etc.

For the life of me I don’t understand the attraction to no fertilizer, no filter no heater, no waterchange tanks. It just holds no attraction to me at all.

 

[FrankZ]

I do water changes mainly to remove dirt that I cause myself from uprooting and general clean up. The big thing it also does is remove the dissolved organic released from the plants as they expel waste while growing.

I have tried reducing water changes in my low tech tanks and it has never worked out well. Things would be fine for a few weeks then crap out. For me weekly 50% at least for all tanks keeps thing happy and healthy.

 

[Art]

What is (are) the main point(s) of doing wc in planted tanks? Reduce waste levels? Has anyone tried to do as few wc as possible? And rely on other methods to maintain proper levels?

Oh boy, you’re opening up a Pandora’s box here for me. I once asked this question on Facebook and was absolutely lit up by MANY, MANY people. I was called a fake influencer, clueless and worse. Unfortunately, questioning water changes is akin to questioning a natural rule of nature.

That being said, let’s dive in !

What does a water change do? ** I’m not counting vacuuming done during a water change **

• Removes a portion of dissolved organic carbon. A portion because we typically will do a partial water change thus leaving some in the water column.
• Removes a part of the plant nutrients that are in the water column.
• Depending on your set up, it may add to your water hardness and provide some nutrients (e.g., my tap adds KH, K and PO4).
• Reduces the amount of tannins and other chemicals that may taint the water thus improving water clarity.
• It dilutes the amount of other “things” in the water that are generated through biological processes in your aquarium’s ecosystem. This captures the unknown that may be classified as “bad”.

Did I miss something?

Reducing or eliminating water changes.

So I did an experiment using specialized carbon to replace water changes. It was inspired by my belief that weekly water changes are one of the most important reasons why new aquarists don’t do plants. Who wants another weekly chore??

The setup used a sump where I hooked up an in-sump reactor full of specialty carbon designed for water but that had large enough pores to minimize it removing larger molecules like EDTA. It was on a T so I could run it whenever I wanted and force all of the aquarium water through it as many times as I wanted. I chose a 10x tank turnover once a week.

I didn’t have an easy way to measure DOC so I relied on indirect observation by seeing if I got algae. I tested for NO3, PO4 and Fe to see if they were accumulating too much. Lastly, I used a white bucket to compare water color before and after running the carbon. The link is to the infamous APD flame-fest.

Hypothesis: Running 10x water volume through specialty carbon would remove 100% of the things a water change only partially does. Therefore, fewer or no water changes would be necessary using this system.

Conclusion:

I ran this way for about 3 months without a problem. Plants and fish were just fine and no signs of nasty algae. The white buckets really showed amazing water color change pre and post carbon.

HOWEVER, after 3 months, I did start to get algae I wasn’t able to get my arms around and I couldn’t explain. Even running carbon twice a week did not resolve the problem.

I guessed that it was because I wasn’t vacuuming the substrate and detritus had built up to a point where it would immediately “contaminate” the water column after I ran carbon. So, I stopped the carbon and started my usual 50% water change + vacuum.

Sure enough, I was able to turn things around. It seems that detritus accumulation in the substrate had a material impact in the proper husbandry that we all do.

This is why I use a water change + carbon combination in my setups. I do the water changes because I have to vacuum and so there is no reason to do a water change. In my mind, a 50% water change reduces DOC by 50%. Simplistic thinking, I know but you get the idea. I then run carbon for 24 hours thinking that it reduces DOC and tannins down to near zero levels (in the water column).

I realize that the substrate and other processes will begin to add back DOC immediately. However, they level in the water column is then at zero which is much better than 50% after a water change alone.

How about a continuous water change?

So this was your initial question. SORRY! I went down a rabbit hole.

I have an APEX DOS that is designed for continuous water changes. The reasons I don’t do them are:

• I would need to have either a water storage system that the Apex would draw from or go straight from tap with some sort of float valve letting water through. I don’t have the room for the storage and I think the direct to tap system is too risky.
• I add Mg to my replacement water to maintain GH. I would need to find a way to add Mg daily. I would likely also have to add the other nutrients as well which would require an automated dosing system. This adds to the complexity of the system.
• Probably most importantly, unlike reef systems, we don’t need to have super low nutrient ranges. A weekly 50% water change is simpler, less risky and should work just as well as a daily water change. So, there really isn’t much additional benefit to doing continuous water changes.

Anyway, thanks for bringing this up. Great topic.

 

[Pepere]

So I did an experiment using specialized carbon to replace water changes. It was inspired by my belief that weekly water changes are one of the most important reasons why new aquarists don’t do plants. Who wants another weekly chore??

I budget an average of 1 hour a week with my 29 gallon tank. That includes weekly, cleaning the glass, in and out, trimming resetting stems, cleaning the lid, weekly light vacuum of substrate, weekly water change and monthly canister filter and lilly pipe clean. Ribbed hoses cleaned every third month.

I think the 50% water change portion itself takes me 15 minutes. If I dint do a 50% water change I would still be draining out at least 10-15% before working in the tank anyway just to be able to work in the tank without sloshing…

When I start up a 75 gallon eventually I am planning on having holding tanks in the basement to pretreat water a day or so ahead of changes and a pump to send it upstairs. I also plan on having a drain plumbed in to the tank stand that I can simply feed my siphon in to.

To my mind, making water changes easier is more attractive than making them less volume or frequent…

But I applaud Art for experimenting…

I am sold on the water changes as it is easier than trying to deal with Algae. Prevention is easier than remediation.

 

[Count Krunk]

Early on I watched videos arguing that you do water changes to reduce nitrate levels.

I had a heavily planted tank with a fair amount of floating plants.
apAs such I had to dose fertilizer to maintain nitrate levels so I figured I didnt need to do water changes.

I also struggled with Algae continuously.

I now do 50% water changes weekly along with using pressure co2 and good flow with a canister filter And plant husbandry techniques that all play a part in minimizing algae growth.

I cant imagine not doing at least 30% water changes on a weekly basis myself. Water changes give you the opportunity to vacuum out debris, detritus, removes plant waste organics, reset fertilization levels and refresh ferts, remove growth limiting hormones, allelochemicals, prevent minerals from concentrating over just doing top offs. etc.

For the life of me I don’t understand the attraction to no fertilizer, no filter no heater, no waterchange tanks. It just holds no attraction to me at all.

Vacuuming the substrate has become popular in reef keeping, and I noticed my tank doing better after I started doing that. Thank you for your input!

I do water changes mainly to remove dirt that I cause myself from uprooting and general clean up. The big thing it also does is remove the dissolved organic released from the plants as they expel waste while growing.

I have tried reducing water changes in my low tech tanks and it has never worked out well. Things would be fine for a few weeks then crap out. For me weekly 50% at least for all tanks keeps thing happy and healthy.

A big difference that is appearing between reefs and planted, there is no dirt in reefs! So the accumulation on the sand bed would seem to be much much lower in a reef.

Oh boy, you’re opening up a Pandora’s box here for me. I once asked this question on Facebook and was absolutely lit up by MANY, MANY people. I was called a fake influencer, clueless and worse. Unfortunately, questioning water changes is akin to questioning a natural rule of nature.

That being said, let’s dive in !

What does a water change do? ** I’m not counting vacuuming done during a water change **

• Removes a portion of dissolved organic carbon. A portion because we typically will do a partial water change thus leaving some in the water column.
• Removes a part of the plant nutrients that are in the water column.
• Depending on your set up, it may add to your water hardness and provide some nutrients (e.g., my tap adds KH, K and PO4).
• Reduces the amount of tannins and other chemicals that may taint the water thus improving water clarity.
• It dilutes the amount of other “things” in the water that are generated through biological processes in your aquarium’s ecosystem. This captures the unknown that may be classified as “bad”.

Did I miss something?

Reducing or eliminating water changes.

So I did an experiment using specialized carbon to replace water changes. It was inspired by my belief that weekly water changes are one of the most important reasons why new aquarists don’t do plants. Who wants another weekly chore??

The setup used a sump where I hooked up an in-sump reactor full of specialty carbon designed for water but that had large enough pores to minimize it removing larger molecules like EDTA. It was on a T so I could run it whenever I wanted and force all of the aquarium water through it as many times as I wanted. I chose a 10x tank turnover once a week.

I didn’t have an easy way to measure DOC so I relied on indirect observation by seeing if I got algae. I tested for NO3, PO4 and Fe to see if they were accumulating too much. Lastly, I used a white bucket to compare water color before and after running the carbon. The link is to the infamous APD flame-fest.

Hypothesis: Running 10x water volume through specialty carbon would remove 100% of the things a water change only partially does. Therefore, fewer or no water changes would be necessary using this system.

Conclusion:

I ran this way for about 3 months without a problem. Plants and fish were just fine and no signs of nasty algae. The white buckets really showed amazing water color change pre and post carbon.

HOWEVER, after 3 months, I did start to get algae I wasn’t able to get my arms around and I couldn’t explain. Even running carbon twice a week did not resolve the problem.

I guessed that it was because I wasn’t vacuuming the substrate and detritus had built up to a point where it would immediately “contaminate” the water column after I ran carbon. So, I stopped the carbon and started my usual 50% water change + vacuum.

Sure enough, I was able to turn things around. It seems that detritus accumulation in the substrate had a material impact in the proper husbandry that we all do.

This is why I use a water change + carbon combination in my setups. I do the water changes because I have to vacuum and so there is no reason to do a water change. In my mind, a 50% water change reduces DOC by 50%. Simplistic thinking, I know but you get the idea. I then run carbon for 24 hours thinking that it reduces DOC and tannins down to near zero levels (in the water column).

I realize that the substrate and other processes will begin to add back DOC immediately. However, they level in the water column is then at zero which is much better than 50% after a water change alone.

How about a continuous water change?

So this was your initial question. SORRY! I went down a rabbit hole.

I have an APEX DOS that is designed for continuous water changes. The reasons I don’t do them are:

• I would need to have either a water storage system that the Apex would draw from or go straight from tap with some sort of float valve letting water through. I don’t have the room for the storage and I think the direct to tap system is too risky.
• I add Mg to my replacement water to maintain GH. I would need to find a way to add Mg daily. I would likely also have to add the other nutrients as well which would require an automated dosing system. This adds to the complexity of the system.
• Probably most importantly, unlike reef systems, we don’t need to have super low nutrient ranges. A weekly 50% water change is simpler, less risky and should work just as well as a daily water change. So, there really isn’t much additional benefit to doing continuous water changes.

Anyway, thanks for bringing this up. Great topic.

thanks for replying in such detail! Your method questioning threads made me want to post up this one.

The consensus so far appears to be, water changes remove dirt/etc that comes from planting. Removes DOC that perhaps the biological and mechanical systems can't.

I am planning to do an automated dosing system, co2 injection, high light, rodi water, and an inert substrate. Combined with a sump running just wall to wall sponges for machinal. swiss tropicals for the sponges.

I will gladly guinea pig for the community, and push the water change question to the max! The system size will be around 150g, so 70g weekly wc isn't something i want to do! lol.

 

[Pepere]

The system size will be around 150g, so 70g weekly wc isn't something i want to do! lol.

Is that because of the time/work involved, or due to water/sewer costs?

I will admit I am not happy with the water and sewer costs. Doubly since I pay sewer costs on every drop that comes in despite evaporative losses and watering my plants with water change water

 

[Count Krunk]

Is that because of the time/work involved, or due to water/sewer costs?

I will admit I am not happy with the water and sewer costs. Doubly since I pay sewer costs on every drop that comes in despite evaporative losses and watering my plants with water change water

i'll use the old water for watering plants, but really it's just effort. Plus with rodi you send a decent bit of water down the drain, or in my case, the yard.

 

[Pepere]

I am fortunate that our local water is very soft. The water district adds a little gh and kh to it to raise ph to prevent lead solder leaching into the water. Tap water is GH and KH of 1 degree..

I dont even have enough potted plants to use 10 gallons of aquarium water weekly…

But I am much happier with how my tanks look since I started weekly water changes.

 

[FrankZ]

Vacuuming the substrate has become popular in reef keeping, and I noticed my tank doing better after I started doing that. Thank you for your input!

A big difference that is appearing between reefs and planted, there is no dirt in reefs! So the accumulation on the sand bed would seem to be much much lower in a reef.

thanks for replying in such detail! Your method questioning threads made me want to post up this one.

The consensus so far appears to be, water changes remove dirt/etc that comes from planting. Removes DOC that perhaps the biological and mechanical systems can't.

I am planning to do an automated dosing system, co2 injection, high light, rodi water, and an inert substrate. Combined with a sump running just wall to wall sponges for machinal. swiss tropicals for the sponges.

I will gladly guinea pig for the community, and push the water change question to the max! The system size will be around 150g, so 70g weekly wc isn't something i want to do! lol.

Check this out

Here is a link describing a modified EI fertilization scheme to reduce water changes. I thought you might be interested in it since it seems to line up well with your maintenance goals.

 

[Count Krunk]

Check this out

Here is a link describing a modified EI fertilization scheme to reduce water changes. I thought you might be interested in it since it seems to line up well with your maintenance goals.

This is what i had in mind. As this is the reefer way of thinking. Dose what the tank needs to maintain good coral growth.

 

[GreggZ]

To my mind, making water changes easier is more attractive than making them less volume or frequent…

I will gladly guinea pig for the community, and push the water change question to the max! The system size will be around 150g, so 70g weekly wc isn't something i want to do! lol.

As described above, water changes provide numerous benefits in a planted aquarium. When things go south, or you want to whip a tank into really great shape, a few extra water changes can do wonders.

I am a big advocate of making your water changes as easy as possible. The easier it is, the more consistently you will do them, and the better your tank will be.

I change 70 gallons at least once a week and sometimes twice a week. But I could walk over to the tank right now and do one and just sit on the couch from across the tank and watch it happen.

Now I have gone to an extreme. I have two 55G gallon drums in the basement. I then ran piping up inside the wall to just above the tank. One pipe for draining. One pipe for filling. One pump in the tank, one pump in the holding tanks in the basement.

So when I want to do a water change I flip one switch to drain, then one switch to fill.

Now this was a good amount of work to set up many years ago, but sometimes I still get a grin while I sit and watch the water draining or filling.

I wouldn't expect many to go to this level, but it pays to give your water change methodology some thought. Like I said, make it easier, and you will be more consistent with water changes. And trust me your tank will thank you.

 

[Count Krunk]

I'm not saying i wont do wc, just asking questions for discussion sake.

I plan on setting up a wc system. I come from reefing, where that is very common. I have a 200gpd rodi unit that will be a key part of the system. @GreggZ

Just want to see how much i can mix methods and still have success.

For some background, ive had reefs (and been on forums) since 2008, so i have solid foundational knowledge haha.

 

[GreggZ]

For some background, ive had reefs (and been on forums) since 2008, so i have solid foundational knowledge haha.

Yep I recognized you know what you are doing!

I have known a lot of reefers come over the planted side over the years. They usually have a leg up as the terminology and complexities are easy for them. Most also have experience with gizmos and gadgets and are good at setting up the mechanicals.

I do think most underestimate what it takes for a full blown underwater garden. It's still complicated, just in a different way. And some things in reef are counterintuitive to growing plants.

For fresh water I don't think the continuous system will work well. Especially in a tank full of stems with lots of uprooting. Anytime you uproot a lot of plants you want to do a LARGE water change.

I am looking forward to seeing where this goes.

 

[Count Krunk]

Yep I recognized you know what you are doing!

I have known a lot of reefers come over the planted side over the years. They usually have a leg up as the terminology and complexities are easy for them. Most also have experience with gizmos and gadgets and are good at setting up the mechanicals.

I do think most underestimate what it takes for a full blown underwater garden. It's still complicated, just in a different way. And some things in reef are counterintuitive to growing plants.

For fresh water I don't think the continuous system will work well. Especially in a tank full of stems with lots of uprooting. Anytime you uproot a lot of plants you want to do a LARGE water change.

I am looking forward to seeing where this goes.

Large wc day and large uprooting day will be closely related i suspect haha.

I'll keep the back to back large wc as a get out of jail card haha.

I'm targeting 55-80g, just need to see what i can find.

 

[Ed Wiser]

Continuously changing water in a reef tank is a bad idea. It causes levels in the tank to crash causing Dinoflagellates.
One has to tread a fine line when you do this type of water change.
Same with no water changes. One has to limit fish load to little to no fish. You have to keep a close check on the elements in your aquarium. DSR Reefing

 

[Count Krunk]

Continuously changing water in a reef tank is a bad idea. It causes levels in the tank to crash causing Dinoflagellates.
One has to tread a fine line when you do this type of water change.
Same with no water changes. One has to limit fish load to little to no fish. You have to keep a close check on the elements in your aquarium. DSR Reefing

That would mean youre changing too much water.

In reef tanks, you mainly have to watch phosphate and nitrate. Those going to 0 will allow dinos to happen.

Regardless of the method, keeping a check on the element levels is always the right idea.

 

[Ed Wiser]

Oh I know reef tanks I have keep them since the 70’s I am the current secretary of MASNA/MACNA. Started keeping SPS in the 90’s.

 

[deepgreen]

Has anyone tried to do as few wc as possible? And rely on other methods to maintain proper levels?

Since the question was if anybody tried to have as little water changes as possible, I want to give a different perspective that only works under very specific conditions. I completely agree with the many advantages of regular water changes and I am always amazed by the beautiful tanks that many of you manage to create with water column fertilization and regular water changes. However, I do in fact try to minimize water changes simply because I do not have much time.

These are images taken within 6 months (no water change) 6 years back. I had more time then and invested more time in the layout (tank has back and front view).


This is one year later, a little messier (after partial trim), but still no water change. These images were not meant for display. I only post them for documentation.



This is three years later, 20 % water change and one chemical treatment after an algae outbreak. Only a snapshot and obviously overgrown before the trim.

Since then, I had another outbreak, but after reducing the light and waiting about 6 months, algae disappeared. I am currently ramping up again and see if I can still get away without a further water change. Current stage (not really nice – camera makes it a little more colorful than it actually is)


This is not a method that works for everyone, especially if you want to always enjoy a beautiful tank. However, it is a method with minimal effort and a moderately nice planted tank ( I refer to the display images at the beginning).

I will update in a few months how it goes, meaning if I can really recover from that recent algae outbreak (very stubborn filamentous green algae) without a water change.


These are my settings:

90 gallon tank, now 10 year old thick layer of ADA Amazonia, Lighting: 1 Fluval Plant 3.0, 2x Aquasky, big canister tank (not cleaned for several years, last time I checked it was completely clean), only root tab fertilization (Osmocote), mainly pruning and very little uprooting, very few to no fish, RO top-off, CO2 cylinder-provided. I do not measure any parameters. Just watch and respond.

Yes, I got algae outbreaks, but these happened when I neglected the tank (too overgrown and plants dying due to lack of light, too much feeding of with surplus food (when I had fish), not enough root tabs).

 

[Count Krunk]

Since the question was if anybody tried to have as little water changes as possible, I want to give a different perspective that only works under very specific conditions. I completely agree with the many advantages of regular water changes and I am always amazed by the beautiful tanks that many of you manage to create with water column fertilization and regular water changes. However, I do in fact try to minimize water changes simply because I do not have much time.

These are images taken within 6 months (no water change) 6 years back. I had more time then and invested more time in the layout (tank has back and front view).
View attachment 4156View attachment 4157

This is one year later, a little messier (after partial trim), but still no water change. These images were not meant for display. I only post them for documentation.
View attachment 4158


This is three years later, 20 % water change and one chemical treatment after an algae outbreak. Only a snapshot and obviously overgrown before the trim.
View attachment 4163
Since then, I had another outbreak, but after reducing the light and waiting about 6 months, algae disappeared. I am currently ramping up again and see if I can still get away without a further water change. Current stage (not really nice – camera makes it a little more colorful than it actually is)
View attachment 4164

This is not a method that works for everyone, especially if you want to always enjoy a beautiful tank. However, it is a method with minimal effort and a moderately nice planted tank ( I refer to the display images at the beginning).

I will update in a few months how it goes, meaning if I can really recover from that recent algae outbreak (very stubborn filamentous green algae) without a water change.


These are my settings:

90 gallon tank, now 10 year old thick layer of ADA Amazonia, Lighting: 1 Fluval Plant 3.0, 2x Aquasky, big canister tank (not cleaned for several years, last time I checked it was completely clean), only root tab fertilization (Osmocote), mainly pruning and very little uprooting, very few to no fish, RO top-off, CO2 cylinder-provided. I do not measure any parameters. Just watch and respond.

Yes, I got algae outbreaks, but these happened when I neglected the tank (too overgrown and plants dying due to lack of light, too much feeding of with surplus food (when I had fish), not enough root tabs).

Thanks due sharing! Very different and still had quite nice results