Flow vs filtration

[LucaG]

Hi everyone,
I have been reading through this forum and the Barr report articles for a while trying to find a confirmation that a planted aquarium without fish ( or very few), regardless of its size, does not require a traditional filter ( external or internal with mech/biological media) but only a powerhead to produce water flow.
I am not talking about the walstad type aquarium but a high tech with high light, CO2 and maybe EI.

If we need to add nitrogen in the routine water fertilization, it would suggest that no enough ammonia is produced to be converted in no3, so why the need of a biological filter ?
What are your thoughts?

In my experience with a heavily planted tanks with a few shrimps only, after the initial cycling period, no ammonia is ever detectable.
For sure decaying plants would cause ammonia but it seems that the whole system copes well without the added livestock waste.

 

[Zeus.]

In my experience with a heavily planted tanks with a few shrimps only, after the initial cycling period, no ammonia is ever detectable.

Correct, the plants roots and substrate give massive biological filtration so the need for a filtration system with large biological filtration is massively reduce. Fish only tanks, tanks with fish and few plants and stock tanks eg fish tanks at LFS, the need for good biological filtration in the filter is critical.
Also worth thinking about the biggest fish in tank that may die and not be spotted, which will breakdown and produce an ammonium/nitrite spike ! IMO having a filtration system with course and medium sponges in our planted tanks filtration system is plenty, if livestock does die and isn't spotted due to holidays the bacteria respond fast enough to take care of any spikes with decaying fish or if the person feeding fish during hols is too heavy handed.

 

[Ria95]

Require - no
If we are to set our goal above that then I would suggest that a plant only tank does still benefit from at least good mechanical filtration. The plants and the small or microscopic animals living in our tanks will still produce detritus which over time gathers on/in the substrate, large leaves, moss and loads the systems in terms of organics or is simply unsightly. Having a filter before the powerhead is an easy way to get rid of some of that detritus.

I would also bring to the discussion that while nitrifiers are important, they are but just a small part of the microbial diversity ( see the many papers recently linked by Darrel). Many of them can build biofilms or be part of them so may benefit from the extra surface given by the biomedia. I’m not sure they are required in higher numbers than could be afforded by the substrate and landscape of a tank. More growth surface usually helps in diversity and microbe diversity usually helps in a robust system. We’ve seen a few reports where bacteria growth was able to move algae away from surfaces. Maybe it’s just a nice to have in some marginal cases, maybe it would benefit most tanks. Marine tanks seem to be more involved about the use of bacteria in a lot of tank management aspects. We have the benefit of a quick water change.

 

[dw1305]

Hi all,

Require - no

You might be interested in @Bart Hazes threads <"Low-flow and no-flow tank setups">. I don't know how he got on long term.

If we are to set our goal above that then I would suggest that a plant only tank does still benefit from at least good mechanical filtration. The plants and the small or microscopic animals living in our tanks will still produce detritus which over time gathers on/in the substrate, large leaves, moss and loads the systems in terms of organics or is simply unsightly. Having a filter before the powerhead is an easy way to get rid of some of that detritus.

That was the decision that Diana Walstad <"Walstad revises"> subsequently came to after the publication of <"Amazon product ASIN 0967377366">.

Personally I'm a <"powerhead & pre-filter fan">.

Many of them can build biofilms or be part of them so may benefit from the extra surface given by the biomedia. I’m not sure they are required in higher numbers than could be afforded by the substrate and landscape of a tank. More growth surface usually helps in diversity and microbe diversity usually helps in a robust system. We’ve seen a few reports where bacteria growth was able to move algae away from surfaces. Maybe it’s just a nice to have in some marginal cases, maybe it would benefit most tanks. Marine tanks seem to be more involved about the use of bacteria in a lot of tank management aspects. We have the benefit of a quick water change.

That one, that is it for me, <"the Coffee, not the froth">.

I want <"belt and braces">, <"plenty of plants, plenty of oxygen"> and a <"diverse microbial assemblage"> to try and keep ammonia levels low at all times.

cheers Darrel

 

[Zeus.]

I would suggest that a plant only tank does still benefit from at least good mechanical filtration.

Yes, mechanical filtration is key to success esp in a high tech tech (CO2 enriched). In my 500l Tank Olympus is Calling the detritus it produced was prolific. Weekly filter cleans was an integral key to keeping it looking good. The sponges was always full of lots of detritus.

 

[LucaG]

Thanks for everyone's inputs,
Flow is key obviously, extra biological filtration add a safety margin.

My aim is to keep things as simple as possible and visually minimalistic in small tanks.
I recently removed the unsightly hob filter on the 30lt cube and swapped for a skimmer increasing flow but decreasing filtration.
On the 20lt I converted a usb micro pump to a skimmer with some 3d printing...
Time will tell...