[obscbyclouds]

My 29 gallon doesn't ever seem to have any detectable nitrate. It is fairly heavily planted (anubias, crypts java fern, wisteria, and hornwort), and I assume the plants are using all of it that's available. I'm using DIY C02 yeast method. Ammonia and nitrites are always 0. PH is about 6.9 and KH is 3.5. Tap is ~7.4-7.6.

I am using a API drop test, and get what I believe are good results using the same test procedure with my 10 gal, my nitrates in that tank start at about 10 ppm right after my weekly 25% change and go up to 30-40 before the next.

My plants appear to be growing, and I weary of changing what seems to be working, but I've heard 0 nitrates can be a recipe for algae. Which i only seem to have a bit of green spot and brown algae on some plants, nothing that I'd call a big deal, or outbreak. Water is clear as could be, and it takes a week for anything to grow on the front wall.

My question is three-fold:
Why do I not have detectable nitrate levels?
Should I be dosing with Flourish Nitrogen, or pure KNO3 (or something else) to increase my levels?
Should I be feeding my fish more? I typically feed them once per day with a once a week fast day and have always done so. My Pleco also gets a wafer replaced by zucchini once time per week right after the lights go out.

Thanks and sorry for going on for so long!

 

[drhank]

Although this isn't my area of expertise, I wouldn't worry too much as long as everything (plants, inverts, and fish) seem healthy. The nitrates are bound to the plant fiber. In a Marine environment you have achieved an ideal situation.

Feeding your fish more would cause more waste elimination which should result in more nitrates, which should help with plant growth.

Perhaps someone with more specific knowledge will chime in. I tend to subscribe to the if it ain't broke, don't fix it adage.

 

[Dmaaaaax]

Aren't hornworts notorious for removing nitrates? I think you are fine as long as your plants look healthy and do not look thin or glassy. They can also utilize ammonia and nitrite, so the waste might not even make it to the nitrate part of the cycle.

If all your fish are max size, you could consider adding more and "overstocking" your tank as many planted tank owners do. This would mean more feeding and more waste, and more nitrates. As long as you can keep it at 10ppm or lower through weekly changes, you are fine.

 

[obscbyclouds]

Thanks both of your for reassuring me. I'm going to keep everything the same for now, as all my plants and fish seem to be thriving. In the future I may get a few more fish and see how that goes.

 

[James0816]

Aren't hornworts notorious for removing nitrates?

Yep...Hornwort is a known aquatic sponge when it comes to sucking up nutrients.

Definately use the "if it ain't broke...don't fix it mentality".

Something else to consider will be if you add any other type of plants in the future. You should make preparations ahead of time for that.

Me...personnally...If it's < 20 ... don't like it. ;o) . Just things you pick up along the way. Especially once you get into dosing dry ferts. And I see you are already on the DIY CO2 bandwagon.

All mine are balanced at 20-40. But then again...I don't keep any nutrient demanding plants in there either. *#3