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.