Plants and water changes.

Divinityinlove

Fish Crazy
Joined
May 13, 2020
Messages
307
Reaction score
65
Location
London
What do you all think about this tank using no filter? when I see something like this, it brings up the question for me about water changes and gravel vac as well.

I do often wonder if doing weekly water changes and monthly gravel vacuuming is removing essential nutrients for my plants. Why remove the ammonia, nitrates and fish waste plants can utilize.. Then add fertilizers? Am I depriving my plants?

The stem plant (hygrophila) I have as my main plant in the tank, was growing surprisingly fast when first introduced to the tank, back then, I did monthly water changes and never gravel vacuumed as I was new to adopting this tank and didn't know much anyway.

Since I've started weekly changes and occasional gravel vac... This plant barely grows and in fact keeps losing lower leaves.

I know I've had discussions here about ferts before and I just found out API does an iron based one I will try...

But I want to hear all experiences, especially from anyone who's kept a tank without a filter. Do these plants do all the filtering necessary?
 
I see many people on Youtube keeping fish for years without a filter (MD fish Tanks) and all their fish are fine! None of them die!
 
Unfiltered tanks? Sure, they work, but they don't work for every fish.

You need to choose species that tolerate low oxygen conditions and come from swamp habitats. Then you have to stock at about 10% of what is usually suggested. I can run an almost unfiltered killie tank with one 1.5 inch fish per 10 gallons. It will go on a long time. It would work with a few of the species I have here, maybe a quarter of them.

Before I put a fish in those conditions, I'd research the natural habitat for the species very carefully.

As for water changes, skipping them is putting yourself far before your fish. You add minerals that are depleted with a water change, and remove hormones and wastes secreted by the fish. I ran a tank from the age of 10 to about 18, in the era before aquarists did water changes. My fish had lifespans about 1/3 of what they do now, and grew to considerably smaller sizes. They lived, but were far less active than they became after I started experimenting with the new fangled idea of clean water.

This hobby existed for several decades before pumps and filters were available. If you go back to the old books, you will see they kept very few of the fish we can keep now, and they stocked at very low levels compared to the modern hobby.

I could pull out my filters and make a video about my miracle unfiltered set up. I wouold get 100 times more hits than I would for a real tank, because people look for what they want to find. Cater to that, and you're laughing.

I can look at a tank and be pleased with it, even if the fish population is so low I don't see fish every time I look. Can you? That's the bottom line.
 
I see many people on Youtube keeping fish for years without a filter (MD fish Tanks) and all their fish are fine! None of them die!

You don't know this any more than the rest of us do. This is like those photos of "algae-free" tanks...there is no such thing if live fish are in the tank. And, none of us can know any fish is "fine" because we cannot talk to it to find out...but we can provide the best and healthiest environment for the species and assume the fish will respond with good health and a good and normal life. A tank with no filter may be good but it all depends upon the tank size (volume), live plant species and number, and the fish load. Many years ago I read a biologist's article that a 4-foot 55g tank housing only six black neon tetras and thick with fast-growing plants would be self-sufficient. I don't think any of us would consider no more than six 1.5-inch fish as the maximum in this large (proportionally) a tank as all we wanted. There was a TV show on fish tanks some years back, can't remember the name, and some "wild" claims were regularly made about the fish and the tank maintenance. A microbiologist who happened to know these guys personally, and their "fish tanks," made it clear that the fish frequently died because of the inappropriate setups, and it was frankly a hoax. Much of what we find on YouTube today is just the same.
 
I do often wonder if doing weekly water changes and monthly gravel vacuuming is removing essential nutrients for my plants. Why remove the ammonia, nitrates and fish waste plants can utilize.. Then add fertilizers? Am I depriving my plants?

First, plants do not use nitrate, so that is simply harming the fish (the higher the nitrate, the longer the fish are exposed, the more harm). Plants use ammonia/ammonium as their preferred source of nitrogen, and unless the tank is overstocked and not biologically balanced, there will never be a shortage of nitrogen (ammonia/ammonium). The decomposition of organics is the primary source of carbon; CO2 is produced by the breakdown of organics as well as the respiration of fish and plants (and some bacteria species). The extent towhich the substrate needs "cleaning" depends upon the whole biological system. I have had some tanks where I changed the water regularly but never touched the substrate for years, and other tanks where the substrate needed cleaning. plants grew equally well in either, provided everything else necessary was covered.

Water changes are not going to harm plants, again assuming things are balanced to begin with. But water changes do improve the health of fish, this is scientific fact.

Since I've started weekly changes and occasional gravel vac... This plant barely grows and in fact keeps losing lower leaves.

This is not likely cause and effect. There are likely missing nutrients (see next comment on the API); stem plants are fast growing, which means more light intensity and nutrients are needed. As soon as one necessity in the light or the nutrients is inadequate to balance the rest, plant growth slows.

I know I've had discussions here about ferts before and I just found out API does an iron based one I will try...

If this is their Leaf Zone, forget it. I know some "say" they had good results, but that is deceiving. Plants need 17 nutrients, not just the two in this stuff, and while a moderate fish load may provide most from being fed, along with substantial water changes, it all depends upon the plants--and fish load/feeding obviously. A comprehensive supplement is better.

But I want to hear all experiences, especially from anyone who's kept a tank without a filter. Do these plants do all the filtering necessary?

I had a 10g tank running for over a year, with no filter and no light. It had a heater (winters got cold without), and was placed in front of a west-facing window for light. Sand substrate, lots of chain swords planted and a thick cover of floating plants (Water Sprite, runner plants from the swords, and Salvinia). A shoal of 12 Boraras brigittae and ten Corydoras pygmaeus, and a couple shrimp (unknown, they arrived with the cories). Water change was 60% very week. This would never work with many of the fish we keep, but it suited these. The water was never crystal clear, not suprising (filters remove microscopic suspended particulate matter which keeps the water clear), and without a light the plants naturally grew toward the rear glass in front of the window light source and it was difficult to see the fish without overhead light. But it was a very healthy tank.

As noted, water changes were and are still essential assuming one wants healthy fish.
 
Water contains a lot more than nutrients plants need. Elements like arsenic, uranium cesium,strontium are also pressent at low levels. Since plants don't need these elements they can build up over time in the tank eventually making it toxic. Water changes are the best way to remove these toxic elements.

Additionally most fertilizers on the market don't have calcium a vital plant nutrient. And most fertilizers don't have enough magnesium, copper and zinc which also are plant nutrients. A water change addeds these nutrients. Most of the copper and zinc in aquariums comes from the metal pipes the water flows through.

Also plant consume nutrients at variable rates so some nutrients in a fertilizer may also build up to toxic levels. Again a water change the gravel vac hellp.

So in conclusion water changes are just as important in a planted tank. However with that said there are people that good plant growth without water changes. Some tanks do better with a smaller less frequent water change while others need more larger water changes. Each tanks different so the water change change

Since I've started weekly changes and occasional gravel vac... This plant barely grows and in fact keeps losing lower leaves.

I know I've had discussions here about ferts before and I just found out API does an iron based one I will try...
The API fertilizer (Leaf zone) only contains iron and potassium. That is only 2 of the 14 elements plants need. Additionally loosing leaves it typically caused by a shortage of nitrogen, potassium, phosphate chlorine, magnesium, molybdenum, and nickel. So additional iron is unlikely to help.

I have found that often plants do well in a new tank due to excess fish waste and minerals in the substrate. Over time these generally deplete and as a result plant growth slows, stops, or the plant dies. In most chases depletion happens in a few months to a year.

When I set up my 5 gallon shrimp tank I used RO water because the tap water tasted bad. I couldn't get anything to grow So I started using fertilizers and still had problems. 5 fertilizers later I decided to make my own and after several years growing plants is not my problem. I still have issues by not with the plants
 
The more plants in a tank, the less ligh that can reach the bottom. Fast growing plants will stop growing much if at all whe deprived of light.

I had as many as 13 planted tanks once, and once used pressurized C02. They all got 50% weekly water changes. They wee are all jungles and regular pruning was usually a must.
 
My Sumatra tank (link in my sig if you wan tot see it) is unfiltered, but has a ton of plants. No CO2, and the only fertilizer is fish poop. The only "tech" in it is the light, the heater, and a tiny pump to move the water around a bit. I do a 10-15% water change once a week, and have never cleaned the sand. It's been going strong for almost two years. Look up "the walstad method" for the science behind this.

But I still do water changes. Nature constantly replenishes water bodies with rain, springs, and runoff. Water changes simulate this.
 
Water contains a lot more than nutrients plants need. Elements like arsenic, uranium cesium,strontium are also pressent at low levels. Since plants don't need these elements they can build up over time in the tank eventually making it toxic. Water changes are the best way to remove these toxic elements.

Additionally most fertilizers on the market don't have calcium a vital plant nutrient. And most fertilizers don't have enough magnesium, copper and zinc which also are plant nutrients. A water change addeds these nutrients. Most of the copper and zinc in aquariums comes from the metal pipes the water flows through.

Also plant consume nutrients at variable rates so some nutrients in a fertilizer may also build up to toxic levels. Again a water change the gravel vac hellp.

So in conclusion water changes are just as important in a planted tank. However with that said there are people that good plant growth without water changes. Some tanks do better with a smaller less frequent water change while others need more larger water changes. Each tanks different so the water change change


The API fertilizer (Leaf zone) only contains iron and potassium. That is only 2 of the 14 elements plants need. Additionally loosing leaves it typically caused by a shortage of nitrogen, potassium, phosphate chlorine, magnesium, molybdenum, and nickel. So additional iron is unlikely to help.

I have found that often plants do well in a new tank due to excess fish waste and minerals in the substrate. Over time these generally deplete and as a result plant growth slows, stops, or the plant dies. In most chases depletion happens in a few months to a year.

When I set up my 5 gallon shrimp tank I used RO water because the tap water tasted bad. I couldn't get anything to grow So I started using fertilizers and still had problems. 5 fertilizers later I decided to make my own and after several years growing plants is not my problem. I still have issues by not with the plants
Where can I research how to make my own? I can't believe there isn't a comprehensive commercial product anyone can recommend. 😣
 
Where can I research how to make my own? I can't believe there isn't a comprehensive commercial product anyone can recommend. 😣

There are several very good plant fertilizers available. Making your own is not easy, as the proportions have to be balanced and the light and CO2 factor in. Studies have shown that an excess of some nutrients can cause plants to shut down assimilation of certain other nutrients. Water changes must be massive or nutrients can build up and cause real problems.

For a low-tech or natural planted tank, meaning one that does not have high light and CO2 diffusion, there are three very good supplements for plants. The calcium is less in these, that's true, because most people have water that is high enough in calcium that it is not necessary. This is where the GH factors in, as GH (general hardness) is primarily calcium and magnesium. What is your GH? As you are in London, I believe you have hard water so the GH is going to be more than adequate for calcium and magnesium.

So, the three supplements are Seachem's Flourish Comprehensive Supplement for the Planted Aquarium, Brightwell Aquatics' FlorinMulti, and The Nutrient Company's TNC Lite. As you are in the UK, the latter is available (not in NA where I am) and from its nutrient list highly recommended. The TNC Lite does not have nitrogen or phosphorus, and this is very good. You will have all the nitrogen and phosphorus plants need from the fish being fed.
 
First, plants do not use nitrate, so that is simply harming the fish (the higher the nitrate, the longer the fish are exposed, the more harm). Plants use ammonia/ammonium as their preferred source of nitrogen, and unless the tank is overstocked and not biologically balanced, there will never be a shortage of nitrogen (ammonia/ammonium). The decomposition of organics is the primary source of carbon; CO2 is produced by the breakdown of organics as well as the respiration of fish and plants (and some bacteria species). The extent towhich the substrate needs "cleaning" depends upon the whole biological system. I have had some tanks where I changed the water regularly but never touched the substrate for years, and other tanks where the substrate needed cleaning. plants grew equally well in either, provided everything else necessary was covered.

Water changes are not going to harm plants, again assuming things are balanced to begin with. But water changes do improve the health of fish, this is scientific fact.



This is not likely cause and effect. There are likely missing nutrients (see next comment on the API); stem plants are fast growing, which means more light intensity and nutrients are needed. As soon as one necessity in the light or the nutrients is inadequate to balance the rest, plant growth slows.



If this is their Leaf Zone, forget it. I know some "say" they had good results, but that is deceiving. Plants need 17 nutrients, not just the two in this stuff, and while a moderate fish load may provide most from being fed, along with substantial water changes, it all depends upon the plants--and fish load/feeding obviously. A comprehensive supplement is better.



I had a 10g tank running for over a year, with no filter and no light. It had a heater (winters got cold without), and was placed in front of a west-facing window for light. Sand substrate, lots of chain swords planted and a thick cover of floating plants (Water Sprite, runner plants from the swords, and Salvinia). A shoal of 12 Boraras brigittae and ten Corydoras pygmaeus, and a couple shrimp (unknown, they arrived with the cories). Water change was 60% very week. This would never work with many of the fish we keep, but it suited these. The water was never crystal clear, not suprising (filters remove microscopic suspended particulate matter which keeps the water clear), and without a light the plants naturally grew toward the rear glass in front of the window light source and it was difficult to see the fish without overhead light. But it was a very healthy tank.

As noted, water changes were and are still essential assuming one wants healthy fish.
As I've commented before, water comes out if my tap with 30+ ppm nitrate but my tank is close to zero, so something in the tank is using it. Whether it's bacteria in the filter media or the plants I don't know, possibly a bit of both, but I do know that if I change more than 15% per week nitrate rises as then I seem to be adding more than it can cope with. So water changes can be bad for my fish if I do more than this. Moreover, if it reaches 30ppm in the tank, plant growth is poor.
As for ferts, I years ago I used Leaf Zone seemingly to good effect, but when I started to read comments about it lacking in most elements I tried Seachem instead and I had an outbreak of BGA. After I defeated that I tried several others but all of them caused algae issues of some sort. I went back to Leaf Zone and had great results again so I will stick with that now and swear by it! I can only assume that my plants are getting everything else they need via fish waste and water changes. Occasionally I get signs of phosphate deficiency and I have a phosphate test kit that confirms that levels in my tank are usually zero. I have made my own phosphate feet and I test weekly and add enough to keep it at 0.5ppm, which is still very low.
The attached photo shows nitrate tests done on my tank water and my tap water, performed at the same time, which clearly shows a massive difference in levels. The water company's analysis confirms normal levels are around 30-35ppm.
 

Attachments

  • IMG_20211101_090908077.jpg
    IMG_20211101_090908077.jpg
    165.8 KB · Views: 35
There are several very good plant fertilizers available. Making your own is not easy, as the proportions have to be balanced and the light and CO2 factor in. Studies have shown that an excess of some nutrients can cause plants to shut down assimilation of certain other nutrients. Water changes must be massive or nutrients can build up and cause real problems.

For a low-tech or natural planted tank, meaning one that does not have high light and CO2 diffusion, there are three very good supplements for plants. The calcium is less in these, that's true, because most people have water that is high enough in calcium that it is not necessary. This is where the GH factors in, as GH (general hardness) is primarily calcium and magnesium. What is your GH? As you are in London, I believe you have hard water so the GH is going to be more than adequate for calcium and magnesium.

So, the three supplements are Seachem's Flourish Comprehensive Supplement for the Planted Aquarium, Brightwell Aquatics' FlorinMulti, and The Nutrient Company's TNC Lite. As you are in the UK, the latter is available (not in NA where I am) and from its nutrient list highly recommended. The TNC Lite does not have nitrogen or phosphorus, and this is very good. You will have all the nitrogen and phosphorus plants need from the fish being fed.
I was using tnc lite and someone from the forum said he thinks it doesn't have 1 or 2 necessary ingredients and suggested finding ingredients list which I could not.. Do you know the ingredients it DOES have? At first it was helping but then when I stopped using it, and started again after 6 months, I noticed it caused algae. Black AND green. (I had black algae before so the spores are there but don't grow. When I fertilize the bba grows)
 
One of the reasons it's hard to get a wide enough fert is that water isn't just water. Above, we have someone who has what I'd consider polluted tap water, with 30ppm nitrates in it. Where large agricultural businesses flourish, water is often affected. I see a lot of midwest US aquarists dealing with issues.

So to make the perfect fert for you, you would need to be a chemist, a botanist and probably retired with a lot of free time...

Sometimes if you look around, you can find local basement companies that make great locally adapted products. There is a degree of trust needed. There's a fellow here who studied chemistry when I think he was in jail, and who makes a really good line of local mixes. I don't use ferts, but his tanks and those of his friends are really beautiful.
 

Most reactions

Back
Top