Local NO3 parameters

[Aeon]

From PUB:

NO3 levels
Water from Choa Chu Kang and Bedok waterworks: 0.5 - 7.0 ppm
Water from other water works: 0.5 - 15.0 ppm

What causes the NO3 levels to rise? increase biodecomposition during warm seasons?

Will this be a likely cause of increased NO3 levels and algae growth during warm seasons, especially in non-densely planted tanks?

[juggler]

From their website http://www.pub.gov.sg/ws_potable_water.htm , they indicated that:

* Water from Choa Chu Kang & Bedok Waterworks: Raw water is drawn from estuarine reservoirs. The treated water is normally supplied to western and eastern parts of Singapore.

** Water from Other Waterworks: Raw water is drawn from upland reservoirs and rivers. The treated water is normally supplied to the rest of Singapore.

Could it be the different sources?

[Aeon]

Upland reservoirs = central catchment area? Seletar, Mandai...
I live in the North so my water is probably from this source, which NO3 range from 0.5 - 15ppm.

I just got a AP Nitrate test kit and found that my NO3 level is 20ppm!! no wonder I'm getting all sorts of algae problems despite good plant health and high CO2. My tank is all glosso so nutrient uptake is slower than rojak tanks so I guess the N from tap water is enough. I have 28 cardinals, 10 Yamatos, 6 Otocinclus. Feeding 1 or 2 times a day. I guess my bioload can maintain the NO3 levels.

I'm gonna stop dosing KNO3 but where do I get my K? Seachem is a little ex when I do my own PMMD.

If my bioload is too high and contributes too much NO3 even when I follow a strict 50% water change a week regime, what can I do to reduce the NO3 level? I don't want floating plants as I want my glosso to get full lighting.

My NO2 level is almost zero or immeasurable, I'm using Bioplast tester for this one. So I guess my biological filtration is pretty efficient.

Do I need to check on PO4?

EDIT

I just tested my tapwater. the NO3 level is close to zero so I think most of my NO3 originates from my tank. I did a 60% change and got a 10ppm reading. I'll change again on Friday to get 5ppm then see if it rises.

[PeterGwee]

Aeon, I can tell you its not the NO3 that you are facing algae problems but the NH4. Too many critters will cause this but lack of other nutrients will too. Generally, when plants don't grow or slow down due to some reasons, something else will grow.

I remember Tom Barr did an experiment last time to determine if high NO3 will cause algae issues. But during the run, he did not see anything even when the NO3 is at 75ppm measured with good lab grade kits.

Regards
Peter Gwee

[Aeon]

My plants are growing really well. There are too many sources of info to convince me of the cause...

Also, my tank is not densely planted and nutrients uptake is pretty much lesser than other densely planted tanks. so Tom Barr's experiment might not apply to my case.

Also in many Japanese literature, including Amano's, high nitrates is one of the factors of algae growth. Yet there are people who get them with zero nitrates.

I guess have to rely on long term experience, observation to tell what exactly is wrong and right.

[theodore]

Assuming that your testkit is accurate, 20ppm of NO3 is perfectly normal (and safe level I may add to maintain) for a planted tank. Have you checked your PO4 level? Glosso is a fast growing plant and you probably do not want to risk starving it of any macros.

You have mentioned that you have sufficient lighting and CO2,. How about your circulation?

[Aeon]

I'm using a rainbar underwater and circulation seems good. Whenever I added my CaCO3 solution into the water, I can see the mist spreading well and fast.

Many times I see recommended NO3 levels of 5-10ppm. For my plant mass, I think maybe I should maintain the lower levels...

hmmm...

[leroyfong]

As per usual, I dose my NO3 and the next day I will definitely see green spot algae. This reason should be due more to my low PO4 levels which measures only 0.25ppm using SERA brand rather than too high a NO3 level. I agree with what Theodore and Peter mentioned that other nutrients rather than high NO3 per se leading to algae growth.

[barmby]

Because its GLOSSO. Temperature might also be another factor. When they dont prosper, algae will.

[Aeon]

[quote:73d781cedc="barmby"]Because its GLOSSO. Temperature might also be another factor. When they dont prosper, algae will.[/quote:73d781cedc]

Sigh, how many times must I say?? my glossos are spreading like weeds. but the algae is still stubborn...

My temp is around 27-28degC. During the cooler seasons I get 25-26degC.

[PeterGwee]

Amano is more of an aquascaper/artist than a plant biologist. From what I have read or seen somewhere, he or somebody from ADA mention that the kits they use to measure the NO3 and PO4 are not that precise and the values are not actually zero but quite low. Translated infos from the journals might not be as accurate as the original as well. Since you mention that your plant growth is great, what you can do is to remove whatever algae you can see in the tank and followed by a large water change to remove any possible spores explosion when algae are stressed. Keep harassing the algae while growing the plants well will work. If it doesn't, I will look at your bio load....you mention your bioload is rather high...how high? Oh, the use of ADA aquasoil doesn't help things at all ime. It simply throws off the pH/KH relationship.

Regards
Peter Gwee