I've often wondered if this could be done realistically or only for certain tank sizes/applications. So in theory if you had a large enough tank with light stocking, could it work?
Is it even possible to have a tank with no filtration?
- Thread starter FINWIN
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I've seen some ppl make it happen. They are always a lightly stocked tank with heavy planting. I see this mostly done with 40-55g tanks but have seen it done smaller and bigger as well, just not as often. For stocking I usually see it being done with some cories and schools of tetras. Granted water changes are still necessary to maintain a balance but otherwise it is a nice concept that is possible to do.
Diane Walstad wrote a book about creating a low tech planted tank called "Ecology of the Planted Aquarium". She's known in the planted community. She goes into specifics about what's required and how it scientifically works. There's no filter, just an airstone/powerhead, heater, and simply lighting for the plants.
I have multiple stock tanks set up outside with a lot of fish in them without filtration. Sunlight causes algae growth and wind or animals drinking breaks up the surface layer. I think it is hard to replicate in an indoor tank. I think you would be fine with air-breathing fish like bettas, gouramis, and various catfish.
Interesting! Except for the powerhead that's the setup I had for 7 weeks with my fish during an emergency. I never thought about it working long term (w/cs were every 2 days though).
I have a little 10g tank set up. I use it as a "nursery" type tank to get my val off to a good start. There's way too much flow in my 180g and the young val just keep coming free from the gravel so this little tank is ideal just to give them a few weeks to establish some good roots which then make it easier to root them in my 180g.
I have a heater and a tiny little resun magi 380 filter in there. The flow rate is pants, even worse when the media starts clogging, so I run it without any media in there whatsoever. It acts just like a powerhead really for a bit of water movement. I have four little corys in there too just for interest.
So basically I have no filtration on it at all, just minimal surface movement for oxygen exchange. Parameters are fine, fish are fine. Minimal feeding. Young val grow well and when they reach a certain size I transfer them to my 180g.
I still have to do water changes of course but the nitrate build up is very slow. Once I have a good thriving colony of val in my 180, pretty close now actually, i'll probably put the corys in my 180g and break this little tank down. So yes it's certainly possible. No doubt you could scale it up but maybe minimal stocking would be the way forward.
I have a heater and a tiny little resun magi 380 filter in there. The flow rate is pants, even worse when the media starts clogging, so I run it without any media in there whatsoever. It acts just like a powerhead really for a bit of water movement. I have four little corys in there too just for interest.
So basically I have no filtration on it at all, just minimal surface movement for oxygen exchange. Parameters are fine, fish are fine. Minimal feeding. Young val grow well and when they reach a certain size I transfer them to my 180g.
I still have to do water changes of course but the nitrate build up is very slow. Once I have a good thriving colony of val in my 180, pretty close now actually, i'll probably put the corys in my 180g and break this little tank down. So yes it's certainly possible. No doubt you could scale it up but maybe minimal stocking would be the way forward.
The best filtration for an aquaiumr is live plants. Even better is if they are planted in substrate. Moreover, live aquatic plants host nitrifying bacteria on their stems leaves and roots. Some will even transport oxygen down and then out of their roots to turn the anaerobic region around the roots aerobic. This results in nitrification happening and that in turns leads to anoxic or anaerobic zones above and below which will use nitrate.
If you change a lot of water, no filter is needed.
There is no such thing as a perpetual motion tank. Sooner or later it will crash without certain additions. The smaller any given ecosystem, the faster it will crash. Even if it is a planet and it takes a long time. Sometime it will do so from internal issues and sometimes it will happen due to external issues.
Tubs and ponds do need some care. It depends on what is going on around/in them.
Personally, I have never been a fan of Walstad.
If you change a lot of water, no filter is needed.
There is no such thing as a perpetual motion tank. Sooner or later it will crash without certain additions. The smaller any given ecosystem, the faster it will crash. Even if it is a planet and it takes a long time. Sometime it will do so from internal issues and sometimes it will happen due to external issues.
Tubs and ponds do need some care. It depends on what is going on around/in them.
Personally, I have never been a fan of Walstad.
Not long ago, my water pump that runs the sump (filter) fried.
Because I'm in a remote area, and due to repercussions of Covid, it took over a month to replace it, so no filtration for a little over a month.
I did replace water frequently, overflowing about 4 gallons per hour from tank into the sump, this broke surface tension in the tank and overflowed old water over the biomedia to keep them alive, the sump then overflowed on the ground (tank is outside on a patio).
The tank is 180 gallons holding most about a dozen 4"-6" fish, and one 12" goby, only the goby died during died outage.
My takeaway is because of the heavy planting (aquatic and terrestrial) filtration is probably not really needed, if the tank is not over stocked, water changes are frequent (I normally do @20% per day), and as long as there is some kind of water movement to facilitate oxygen/CO2 gas exchange.
Average aquatic planting of the tank
Below terrestrial plants growing from the surface, tank ends.
Because I'm in a remote area, and due to repercussions of Covid, it took over a month to replace it, so no filtration for a little over a month.
I did replace water frequently, overflowing about 4 gallons per hour from tank into the sump, this broke surface tension in the tank and overflowed old water over the biomedia to keep them alive, the sump then overflowed on the ground (tank is outside on a patio).
The tank is 180 gallons holding most about a dozen 4"-6" fish, and one 12" goby, only the goby died during died outage.
My takeaway is because of the heavy planting (aquatic and terrestrial) filtration is probably not really needed, if the tank is not over stocked, water changes are frequent (I normally do @20% per day), and as long as there is some kind of water movement to facilitate oxygen/CO2 gas exchange.
Average aquatic planting of the tank
Below terrestrial plants growing from the surface, tank ends.
My brother has a 29 gal, sand substrate, heavily planted with Cory cats, some shrimp and a few other fish I’m sure I’m leaving out. No filter and has been going strong for close to two years now. He does water changes every other day and everything seems quite healthy.