Is there a point to mechanical filtration?

[Morcs]

I know it seems like a silly question, but with a thought, it actually isnt.

So what does mechanical filtration actually do?

- It sucks up any left over food, debris, and poo.

What are the advantages of this?

- only that it keeps your tank looking clean.

When really, what else does it do? not much really. Sucking up all the detrius doesnt actually benefit much.

If the waste is left in the tank, it breaks down, releasing ammonia > higher nitrites > higher nitrates > more water changes.

If the filter sucks up all the poo, its breaks down (probably quicker due to pressure and water movement within a filter) releasing ammonia > higher nitrites > higher nitrates > more water changes.

Obviously with well planted tanks leaving poo and left over food is fine as the plants absorb it, as they also absorb nitrates.

The only ways around it are:

-Clean crap from filters regularly (HOB filters not a problem, but i wouldnt be keen to open my canister on a weekly, fortnightly or even monthly basis)

-Vacuuming. This is probably the only answer - but only if most of the waste is able to be vaccuumed.

I was just pondering this, as when my monster fish grow larger, the bioload is going to be very heavy - I have adequate filtration (a canister and HOB, combined 9x turnover.) Nitrates get as high as 10ppm weekly before water changing at current, and I really wouldnt want to be doing any more.

So, my idea was, when I do go barebottom (once I feel the bioload is heavy enough) Im going to raise both of my intakes so they are at about half tank height or higher, and have my powerhead with spray bar along the bottom - hopefully retaining good bio turnover, good surface movement, and pushing all the debris to one up of the tank where it can be very very easily vacuumed up before its allowed to breakdown.

Is my line of thinking correct?

Discuss.

[alanmin4304]

Pretty much. The filter collects gunge which collects bacteria that carry out the nitrogen cycle. I have a number of tanks with no filtration or aeration and they are fine because they are lightly stocked. I have a few other tanks with small filters that realy only stop temperature layering. I have a good sized filter on the turtle tank because they are fithy beasties. It is all about balance.

[oneeyedfrog]

I was reading up on algae scrubbers after reading the following link posted on this forum.

http://www.aquariumslife.com/saltwater- ... er-screen/

and they seemed to agree with you that there is no point to collecting the poo/ uneaten food and storing it within the tank system.

Quite interesting.

heres another site

http://www.algaescrubber.net/forums/index.php

[suphew]

The mechanical filter stops the gunk getting onto the noodles etc, the pores on noodles and other splintered type media's get blocked very easily causing them to loose effectiveness quickly. If you could stop all the solids getting into your biological filter it would never need cleaning. So in a nut shell the mechanic filter actually saves you from having to clean your filter so often.

[Morcs]

The mechanical filter stops the gunk getting onto the noodles etc, the pores on noodles and other splintered type media's get blocked very easily causing them to loose effectiveness quickly. If you could stop all the solids getting into your biological filter it would never need cleaning. So in a nut shell the mechanic filter actually saves you from having to clean your filter so often.

Thanks for that, I did overlook that point

My canisters noodles always need a bit of a rinse in the canister water when its apart for cleaning

Filtration is overrated :lol:

[Caryl]

Filters are a relatively new invention in aquaria. They make life easier for the majority who are too lazy, or don't have time, to do regular, daily, water changes.

If you plant it well, keep the sticking level low, and maintain a strict maintenance regimen, you can keep fish without any filtration at all.

[Morcs]

Filters are a relatively new invention in aquaria. They make life easier for the majority who are too lazy, or don't have time, to do regular, daily, water changes.

If you plant it well, keep the sticking level low, and maintain a strict maintenance regimen, you can keep fish without any filtration at all.

This is true. Also with the correct balance, a well planted tank, lightly stocked tank will not need any waterchanges. ever.

[whetu]

Hmmm... interesting subject.

My two cannister filters integrate several different functions, and for that reason I am happy to have them there. Here is what they do:

• Keep the water circulating in the tank, so it has consistent temperature and chemical concentrations throughout
  
• Create surface agitation, so helping gas exchange (O2 for CO2)
  
• Offer a well-aerated home for good greeblies (biological filtration)
  
• Gather a lot of the gunk together to make it easy to remove from the system in one go (mechanical filtration)
  
• Help make the water look clear (mechanical filtration)
  
• Increase the total water volume of the tank (although each filter holds only about 7 litres of water so 14 litres extra capacity isn't particularly significant)

I suppose the least important of those are the two mechanical filtration functions - gathering all the gunk in one place and making the water look clear. Good circulation is the key to the rest, and could be just as easily achieved with a powerhead in the tank.

I recently cleaned out one of my filters after it had been running for 15 months. There was a fair bit of gunk in the bottom, but not so much that it blocked up the system or reduced flow through the filter. If it had a pre-filter to stop leaves going in there, it would have been even better. I probably could have left it uncleaned for much longer without any ill effects (and will do so next time).

So yes, in summary I agree with the assessment that the mechanical filtration is the least important part of the system and you could probably do away with it altogether without disadvantaging your fish.

[suphew]

Filters are a relatively new invention in aquaria. They make life easier for the majority who are too lazy, or don't have time, to do regular, daily, water changes.

Dad still has the undergravel and air powered sponge filters he started using before I was born, been 40+ years now. Modern powered filters use the same filtering concepts that have been used for decades.

[Caryl]

Still relatively new compared to how many years people have been putting fish in aquaria