Max Nitrate for Corys

[Oblio]

I'm really liking these guys and want to keep them healthy and happy.
I've noticed many posts stating that Corys do not like Nitrate. What is a recommended maximum value for an established tank?
My tap water is pretty much zero, so it should be easy to keep it at an acceptable level.
I have 4 Spotted and 4 Albino in 125 gal with 18 Tetras.
3 small Kleiner Bar Swords (hope to increase plants in the future)

 

[FF_Member146894]

keep the nitrates as low as you possibly can
you can help decrease nitrates by increasing the volume and frequency of water changes or adding some terrestrial plants such as pothos (you can read a good thread on the topic of terrestrial plants here, but note that the use of terrestrial plants should not mean that you need to reduce the frequency of water changes)
many members including myself keep their nitrates at regularly 5-10 ppm (if not undetectable)

 

[Byron]

I agree. No fish we keep "like" nitrates, any more than ammonia or nitrite; all three are toxic to fish. Nitrate is more tolerable, depending upon the level, fish species, and exposure time. But the habitat waters of all aquarium fish have zero or next-to-zero nitrate, so that should tell us something--the fish will always be better with nitrates as low as possible, simply because their physiological systems have evolved not having to deal with nitrate.

Assuming nitrate occurs solely within the aquarium, and is not present in the tap water, it is fairly easy to keep nitrate at or near zero. Not overstocking, not overfeeding, keeping the filter spotless, regular substantial water changes, vacuum the substrate during water changes if fish are "messy," and live plants, particularly fast growers like floating plants.

Aquatic plants keep nitrates low (sometimes zero depending) by using up most of the ammonia/ammonium as their preferred source of nitrogen. They are faster than the nitrifying bacteria at this, with the result that nitrite is therefore kept minimal and nitrate the same; plants do not produce nitrite or nitrate like nitrifying bacteria/archaea do. Terrestrial plants were mentioned above...these use nitrate, and the roots must be in the water but the leaves in the air. This means a tank that is open for the plants to some degree, or use the filter for the roots. Tanks are best covered, as fish, even cories, will jump at night. And there are other reasons too, but that is outside this discussion.

 

[Oblio]

Thanks @realzalio . Recently averaging about 7 ppm with a max of 10. With 125 G I want to reduce both the time spent and quantity of water but still keep them healthy.

 

[Oblio]

keep the nitrates as low as you possibly can
you can help decrease nitrates by increasing the volume and frequency of water changes or adding some terrestrial plants such as pothos (you can read a good thread on the topic of terrestrial plants here, but note that the use of terrestrial plants should not mean that you need to reduce the frequency of water changes)
many members including myself keep their nitrates at regularly 5-10 ppm (if not undetectable)

This actually looks pretty cool. As a side note, I had what looks like a Pothos in a house I sold, grown from a tiny planter with vines running some 20-30 ft on fishing line around the dining area. When I moved out of state I rented the house to a close friend who cared for the plant and it thrived. When I eventually sold the house, the buyer put the plant as a condition of sale (his wife loved it). When my renter moved, his wife (who also loved the plant), removed it, along with yards of vine, and the deal nearly fell through. I still remember when my agent called me and said 'We have a problem, and you won't believe what it is'. It cost me thousands of dollars in additional 'fixes' to the house to make things right. I can laugh now, but not so much then.

 

[Colin_T]

Try to keep the nitrates as close to 0ppm as possible, and under 20ppm at all times. This is for all fish, not just Corydoras. 20ppm nitrate should be the maximum any fish is exposed to and preferably less.

Unfortunately for many of our UK members, and people in other parts of the world, 20ppm nitrate is less than what they find in their tap water, so they have to try and cope with what they have.

 

[Oblio]

Try to keep the nitrates as close to 0ppm as possible, and under 20ppm at all times. This is for all fish, not just Corydoras. 20ppm nitrate should be the maximum any fish is exposed to and preferably less.

Thanks Colin, Nitrates 7 today (a guess with API) , WC scheduled tomorrow.

 

[itiwhetu]

I aim to have zero nitrates, I do it with plants and I make sure that I have the largest biological filter possible. Therefore, I use gravel instead of sand and why I like under gravel passive filtration. The water changing levels have little do with low nitrates if you get the other things right. The correct stocking levels, the right amount of plant and the correct type of filtration.

 

[JuiceBox52]

I aim to keep mine under 5, but closer to zero is better! One of my clients (fish tank cleaning) really struggles to keep hers under 15, and you can tell the fish are stressed by it

 

[itiwhetu]

I aim to keep mine under 5, but closer to zero is better! One of my clients (fish tank cleaning) really struggles to keep hers under 15, and you can tell the fish are stressed by it

Zero is the aim, stock levels, plant, filtration, water changes. It is manageable

 

[Oblio]

Just completed a 50% WC, Nitrates measure at ~3 as expected. I always feel bad for the fish during the WC, all the chaos, algae removal etc. Did a thorough substrate vacuuming too. I also planted one on my plants that was in a piece of driftwood into the gravel substrate along with a tab to feed it. I don't yet have liquid fertilizer since I don't want to change to many parameters/variables at once.

 

[Oblio]

keep the nitrates as low as you possibly can
you can help decrease nitrates by increasing the volume and frequency of water changes or adding some terrestrial plants such as pothos (you can read a good thread on the topic of terrestrial plants here, but note that the use of terrestrial plants should not mean that you need to reduce the frequency of water changes)
many members including myself keep their nitrates at regularly 5-10 ppm (if not undetectable)

Picked up a nice Pothos at Lowes today, only $7 in the discount rack. I popped one of the smaller stalks out, cleaned the roots in tap water and placed in the tank to see how it does. For now, I just adjusted the cover to hold the plant before I invest in a more substantial planting mechanism.