Nitrogen levels, filtering and gravel vacuuming questions

[ciantarah]

I apologize in advance for a very lengthy post... I have a lot of questions.

I have a 29 gal freshwater community tank, lightly planted. I'm using the Aqueon QuietFlow 30 (200gph) HOB filter that was included with the tank when I bought it. I have been using the same filter cartridge since I got the tank 7 months ago... I rinse it gently once a month or so in used aquarium water, based on what I learned here.

My ammonia and nitrites are at zero, but my nitrates are 60ppm after a 30% pwc. I had gotten lazy about PWC's... which is probably why nitrates are so elevated. I planned to do frequent PWCs and get a lot more plants to fix this issue.

However, one of my friends who has kept freshwater fish for a long time told me that plants won't help much. He also thinks my filter is inadequate. He claims that if I had a second filter, there would be sufficient "room" for de-nitrifying bacteria (the ones that convert nitrates into N2 gas) to grow.

After some research on the topic, I found that de-nitrifying bacteria are anaerobic. I can't imagine how a regular HOB filter would ever harbor such bacteria. In fact, all the information I read pointed to de-nitrifying bacteria being a marine aquarium thing (there is de-nitrifying filter media for marine aquariums, and also it happens in live rock/sand... I found nothing meant for freshwater). These bacteria can live in freshwater substrates as well, but if they don't get at least a little oxygen, they can release poisonous hydrogen sulfide. Supposedly plants help prevent this... but the possibility of hydrogen sulfide sounds like a serious matter.

So I guess this brings me to my questions regarding filtration: Is my filtration adequate for my tank size?

Will I see an improvement in water quality with a better filter like the AquaClear one I saw mentioned in other threads?

Can any filtration media safely assist with nitrogen removal in freshwater tanks?

How effective are plants at removing nitrates? Is my friend right about more plants not really helping much?

Also, I read that vacuuming gravel is important for nitrate reduction. But I have live plants so it's hard to vacuum without disturbing/possibly uprooting them. In addition, I made the mistake of putting sand on one side of my aquarium (I wanted one side to have a sort of sandy beach look, mostly because I thought my kuhli loaches would like digging in it). This didn't work... the gravel and the sand combined so now I have pea gravel with sand mixed in just under the surface. If I vacuum I start sucking up sand and stirring it all around.

So, given that I will be planting even more heavily than I am already and there is sand in the tank, do I still vacuum? Tips on doing this properly would be appreciated.

 

[barterking85]

Ok your filter is not good enough cut the rating in half and you see the true results your filter would be fine on a 15 gallon I would get another filter or run 1 ac110

Plants help ALOT with nitrates but that does not mean no more pwc

Yes still vacume but try to hover above the sand and if you can add more sand on top of the gravel it will settle into the gravel over time and will make planting easier and when it packs you can just run your vac over top and you will see the debris get sucked up cause it can't settle into the substrate

 

[ciantarah]

OK, that was really helpful! Thanks.

I knew I'd still have to do pwc I had noticed that the sand made planting easier, and am relieved to know it's not a bad thing. Any suggestions on how to add more without making the water all cloudy for a bit? (I did rinse it beforehand, but it took awhile for it to settle).

 

[jetajockey]

densely planting with good lighting will end up knocking your nitrates out completely if you aren't careful. Keeping a well planted - well lit tank actually involves testing periodically for nitrates to get an idea of how much to intentionally add to the system since kno3 is one of the macronutrients needed for plant growth.

 

[ciantarah]

Good to know... and here I had been worried that lots of plants wouldn't be enough to fix the issue I'm a bit worried about lighting, too, and whether my one 6700K florescent bulb is up to the task of a densely planted tank... but that's probably for another thread in another forum

 

[jetajockey]

It depends on the fixture type, assuming that it is a single t8 bulb, probably not, it'll maintain the plants but you have to remember that the amount of nutrients (nitrogenous waste included) that the plants are going to use is directly proportional to the amount of lighting and co2 that the plants are receiving.