Hardy Fish - Practically No Filter!

[mrlewis1978]

In my bedroom I have a 120 litre tank with 5 burmese loach, 4 golden barbs, a pair of dwarf gourami and a juvenile bristlenose. The tank is planted with sand substrate and bogwood. The tank has been set up since Christmas. I bought the tank second hand with an internal filter (Fluval 4+). The tank has been shut down recently, so when I set it up I ran it with with an existing cycled internal filter for a month, then let the Fluval 4+ go it alone. The filter has always had an excellent flow and no issues. All of the fish in the tank have flourished and seem really happy and lively. I decided that I would give the filter a clean this month as it had been set up for six months. I took the filter out to clean in a bucket, opened it up and it was empty. No sponge, no media, nothing. My fault for not checking when I bought it, but I am more suprised that I havent encountered any deaths or ill health with a filter that was effectively pushing water around a tank.

Does this surprise anyone else as much as me? Anyone had similar experiences?

 

[ZoddyZod]

have you tried a water test to see if any ammonia or nitrite is present? Would be really interesting to find out.

 

[N0body Of The Goat]

Now shock us all and tell us the stats are perfect with a liquid test kit!

 

[manxjason]

In my bedroom I have a 120 litre tank with 5 burmese loach, 4 golden barbs, a pair of dwarf gourami and a juvenile bristlenose. The tank is planted with sand substrate and bogwood. The tank has been set up since Christmas. I bought the tank second hand with an internal filter (Fluval 4+). The tank has been shut down recently, so when I set it up I ran it with with an existing cycled internal filter for a month, then let the Fluval 4+ go it alone. The filter has always had an excellent flow and no issues. All of the fish in the tank have flourished and seem really happy and lively. I decided that I would give the filter a clean this month as it had been set up for six months. I took the filter out to clean in a bucket, opened it up and it was empty. No sponge, no media, nothing. My fault for not checking when I bought it, but I am more suprised that I havent encountered any deaths or ill health with a filter that was effectively pushing water around a tank.

Does this surprise anyone else as much as me? Anyone had similar experiences?

Bacteria will happily grow on substrate, plants and decorations etc. It will of course prefer a flow of a filter as the water movement adds more oxygenated water to the tank.

Look up the Diana Walstad method. This involves using garden soil as a substrate, with a cap of sand/gravel. These tanks can run without a filter, and flourish. Very interesting - she actually wrote a book on the matter. She's an admin on an american forum - have a quick google on it

 

[mrlewis1978]

I will do a water test tonight (liquid) as I did this last night before bed. Luckily I had some spare filter foam which I cut and put in. I will post results on here. They are such a (seemigly) healthy bunch in the tank though, I would be suroprised if water quality is bad. Is it possible there is enough surface inside the filter for enough bacteria to have grown?

manxjason - thank you - will look it up.

 

[Man of fish]

What were the stats last night?

 

[mrlewis1978]

I didnt check the stats to be honest with you as I cleaned the filter late, and made my discovery.

 

[Man of fish]

Ahh I thought you meant you tested the water last night. I gotcha now

 

[Aqua Tom]

Results?


Tom

 

[mrlewis1978]

So the readings Ammonia 0, Nitrite 0, Nitrate 5ppm.

The tank is a planted tank with sand, so potentially could it have cycled in the Diana Walstad method mentioned above? Al the fish look healthy, happy and lively like they normally do.

 

[mrlewis1978]

Oh well tried uploading picture didnt work

 

[FishBlast]

Interesting.
Maybe an ecosystem has been established there, with plants + what's left of the bacteria working to provide fish with better water and fish providing food for them.

 

[mrlewis1978]

I hope so, would be a shame now that i have put sponge in for the tank to suffer

 

[Dazzler666]

That is very interesting!!! You mean all this time I've been purchasing filter media & I didn't need it!!! lol.
Very interesting reading mind. It's great when an experiment comes together!! he he.

 

[mrlewis1978]

I feel like a 'bad mother'. Im just glad readings are all ok and the fish healthy. It can only go onwards and upwards with media in the filter! I imagine that I have been lucky because all the fish have been juveniles (except the pair of dwarf gourami)with the combination of planted and sand..