Have I been misinformed about filters?

[cupofjoel]

After being a member on this forum for several months I have learned so much. But before becoming a member I was taught to have as much bio-media in my canister filters as it can hold. Currently I have a biomaster 600 which allows me to have around 1-2 pounds of seachem matrix with two trays worth of sponge and 6 smaller prefilter sponges on the prefilter feature of the canister filter. https://www.amazon.com/dp/B07DFMWTSW/?tag=ff0d01-20

But, now that I'm a bit more educated I was thinking that maybe all I need the filter for is to FILTER the water from floating waste...to act as a trash can that I empty and rely on floating plants and the beneficial bacteria that lives on my gravel, wood, rocks, and everything else in the tank for my biological filtration. Thoughts?

On a side note I have tons of deteritus that has settled in certain parts of my tank ever since I took out my wavemaker as to not disturb my floating plants. I feel that all that deteritus on the top of my gravel can't be good in the long run for algae issues. I do gravel vacuum, but can get lazy and some places are hard to reach. Thoughts? Should I put my wavemaker back and risk getting water on top of my floating plants and see them struggle/rot?

 

[Byron]

But, now that I'm a bit more educated I was thinking that maybe all I need the filter for is to FILTER the water from floating waste...to act as a trash can that I empty and rely on floating plants and the beneficial bacteria that lives on my gravel, wood, rocks, and everything else in the tank for my biological filtration. Thoughts?

Correct. When live plants are present, assuming there are sufficient, and assuming the fish stocking is balanced with the tank to begin with, the filter is solely needed for mechanical filtration and providing water movement (depending upon the needs of the fish in this respect). Biological filtration meaning the nitrification bacteria is actually counter-productive in this situation. The plants take up ammonia/ammonium faster than the AOB (ammonia oxidizing bacteria) and plants can take up a lot, and it is occurring day and night. This is one reason I suggest that new tanks with live plants do not bother with "cycling," it is not beneficial and might sometimes be the opposite. The bacteria species that live primarily in the substrate will include nitrifiers but far more other species of aerobic and anaerobic bacteria that are even more essential.

On a side note I have tons of deteritus that has settled in certain parts of my tank ever since I took out my wavemaker as to not disturb my floating plants. I feel that all that deteritus on the top of my gravel can't be good in the long run for algae issues. I do gravel vacuum, but can get lazy and some places are hard to reach. Thoughts? Should I put my wavemaker back and risk getting water on top of my floating plants and see them struggle/rot?

I use the water change to vacuum this out if it is present. Organics do feed plants, but you are correct that they can become too many, and that can mean high nitrates, algae, cyanobacteria, and other perhaps less troublesome but still detrimental issues. My 40g tank which houses 41 cories and 18 other fish never gets any substrate "cleaning," just a 70-80% weekly water change, and I do rinse (under the tap) the Aquaeon Quiet Flow filter each time. I use the filter for water movement, especially surface disturbance, as the increase of CO2 during the night can be seen to affect the fish without this.

 

[Retired Viking]

I agree with @Byron and have been doing what is called planted or silent "cycling" on all my tanks now. It is a simple and natural way to "cycle" your tank. It is not really cycling because the plants absorb ammonia and they also improve the quality of the water taking in CO2 and giving oxygen during the day . I have never had a ammonia reading above 0.

 

[cupofjoel]

Correct. When live plants are present, assuming there are sufficient, and assuming the fish stocking is balanced with the tank to begin with, the filter is solely needed for mechanical filtration and providing water movement (depending upon the needs of the fish in this respect). Biological filtration meaning the nitrification bacteria is actually counter-productive in this situation. The plants take up ammonia/ammonium faster than the AOB (ammonia oxidizing bacteria) and plants can take up a lot, and it is occurring day and night. This is one reason I suggest that new tanks with live plants do not bother with "cycling," it is not beneficial and might sometimes be the opposite. The bacteria species that live primarily in the substrate will include nitrifiers but far more other species of aerobic and anaerobic bacteria that are even more essential.



I use the water change to vacuum this out if it is present. Organics do feed plants, but you are correct that they can become too many, and that can mean high nitrates, algae, cyanobacteria, and other perhaps less troublesome but still detrimental issues. My 40g tank which houses 41 cories and 18 other fish never gets any substrate "cleaning," just a 70-80% weekly water change, and I do rinse (under the tap) the Aquaeon Quiet Flow filter each time. I use the filter for water movement, especially surface disturbance, as the increase of CO2 during the night can be seen to affect the fish without this.

Thanks for the info!

My floating plants now cover around 25% of my 75 gallon tank. They grow fast. I am sure it will cover 90% in 3-4 more weeks. Will my floating plants suffer if I don't dose with any ferts?

 

[seangee]

None of this is to say its not a good filter - it is. Part of the counter productive effect that @Byron refers to is the belief that you have a good (and big) filter so don't need to clean it that often. This then becomes a very efficient nitrate factory. I used to have 2 canisters on my 200l tank. I replaced these with a simple HOB with 2 sheets of coarse sponge in the bottom. The matrix that came with it is still on a shelf in my garage. After a while I realised I was not getting enough circulation with all the floating plants I have, and my powerhead was way too powerful for my fish.

So I reconnected the smaller of the filters - put a fat pipe on the outlet to reduce flow and just a single layer of sponge in each of the media trays. I too treat these as purely mechanical filters and water shifters. I also rinse mine under the tap as I am not bothered about the BB in the filter. One really positive aspect of this was that I lost power for 8 hours on Sunday. Naturally I did test for ammonia once the power was restored, and again the following morning, but there was absolutely no trace in the water.

 

[Byron]

Thanks for the info!

My floating plants now cover around 25% of my 75 gallon tank. They grow fast. I am sure it will cover 90% in 3-4 more weeks. Will my floating plants suffer if I don't dose with any ferts?

Possibly, it rather depends upon the available nutrients. Even in my tanks with a decent fish load, I find I need to use liquid fertilizer (though not much) to keep the floating plants healthy. Floaters have the aerial advantage; with leaves (or fronds if ferns) at the surface they can assimilate CO2 from the air, and this for plants is about four times faster than when submerged. So with plenty of CO2, and good lighting above them, they will grow very rapidly--but only until something they need is no longer sufficient. It is unlikely to be nitrogen (ammonia/ammonium), so it could be one of the other nutrients.

 

[Retired Viking]

I use Seachem Flourish Comprehensive at 1/2 dosage for my floating plants and flourish root tapes for my rooted plants. Depending on how many fish you have and the amount of waste/ammonia they produce you may just rely on the fish for your plants that draw what they need from the water.

 

[seangee]

My floating plants now cover around 25% of my 75 gallon tank. They grow fast. I am sure it will cover 90% in 3-4 more weeks. Will my floating plants suffer if I don't dose with any ferts

Mine do. I dose half the recommended dose of flourish comprehensive a week. If I miss a week or even 2 its no big deal. Miss 3 or 4 weeks and I can start seeing the difference. They perk up quickly enough if I just resume the schedule - no need to compensate for what they missed.