Nitrates Vs Fertilizers

[Faffer]

Hi

I have been gradually adding more and more plants over the course of the last few months in an attempt to reduce nitrates in my tank. About 3 months ago, I switched my gravel substrate to sand, and in doing so, I also added a thin layer of fertilizer before laying the sand on top.

Before switching substrate, my nitrates were always between 5 and 10 ppm. Since switching, I can't seem to get the nitrate below 40ppm. My tap water comes out at just under 40ppm.

Would having a rich substrate prevent the plants from taking up nitrates in the water? Should I change the substrate again, but just use sand with no ferts?

 

[KeithV]

Hi

I have been gradually adding more and more plants over the course of the last few months in an attempt to reduce nitrates in my tank. About 3 months ago, I switched my gravel substrate to sand, and in doing so, I also added a thin layer of fertilizer before laying the sand on top.

Before switching substrate, my nitrates were always between 5 and 10 ppm. Since switching, I can't seem to get the nitrate below 40ppm. My tap water comes out at just under 40ppm.

Would having a rich substrate prevent the plants from taking up nitrates in the water? Should I change the substrate again, but just use sand with no ferts?

Here's what I found, you prob already know these things but here ya go, hope it helps:

Detritus, decaying plant material, dirty filters, over-feeding, and over-stocking the tank, all contribute to increased production of nitrates. When the nitrates rise above 10ppm you're at risk for copius algae growth because thats more nitrates than the plants can uptake. Nitrate spikes happen late in the nitrogen cycle and since you already have plants to help heres what you could do IMO:

Keep the tank clean – Waste ultimately produces nitrates. Cleaner tanks produce fewer nitrates in the first place.


Don’t overfeed the fish – Overfeeding is a significant contributor to excess nitrates and other undesirable wastes, such as phosphates.


Water changes – Performing regular water changes with water that has little or no nitrates will lower the overall nitrate level in the tank. RO/DI water is an excellent choice for keeping nitrate levels low since your tap water is high in nitrate levels to start with.

 

[Truck]

40ppm isn't really a problem, and considering plants will take in a maximum of 5ppm daily at crazy lighting levels your plants are probably removing 1-2ppm a day, just keep up with the water changes and you have nothing to worry about.

 

[RadaR]

40ppm isn't really a problem,

Agreed, infact I'd go a step further and say it was completely nothing to worry about. 40ppm of NO3 comes out the tap, ok, atleast you know that's not because you're feeding lots or experiencing decaying matter which is converted from harmful ammonia to nitrite then nitrate.
I'd say your plants were lucky to have such a good supply of NO3 from the tap. It means you don't need to fork out money for a fert that contains Nitrogen. Instead just do a few water changes a week. In additon, this helps lower the potential of algae because each water change you do will be reducing the algae spores and undetectable ammonia in the tank.


P.S. This is all assuming that your tapwater is 40ppm because of what the test kit tells you. Nitrate test kits are innaccurate to say the least and are useless after a year or so anyway. I wouldn't trust a word they say personally unless you calibrated them.

 

[Mikaila31]

40ppm out of the tap is quiet high for drinking water. Not unsafe, but high. I agree with Radar about nitrate kits. You should have a 2nd or 3rd test done by a LFS that uses liquid tests. Compare their results to yours, their should not be a major difference. 40ppm in the tank is fine. Thats the same nitrate levels I have and mine and fish are 100% okay with it. They spawn regularly. The eggs don't do too good in my water. Hatch rate is low, probably to do a combination of micro organisms, nitrate, and hard water they have to deal with. Doing a mix of 50/50 RO and tap helps with hatching and keeping very young fry alive. I only see 20ppm of nitrates out of the tap.