Do I need more Nitrate if tap water has enough?

[Akmaliano]

Maybe a slightly dumb question, but if my tap water report shows 21.3ppm Nitrate, can I stop adding, or at least reduce, the KNO3 to my macro mix?

Thanks

PS. I'm going to dose sufficient potassium separately anyways as I have a few plants with pinholes on their lower leaves

 

[ian_m]

No, ignore your water report. Going down that route and changing things based on somebodies water report, is the start of algae and associated tank problems.

The water report is for their test point on a particular day and not your tap water today.

Just keep dosing EI, no issues with excess inorganic sourced nitrates. I accidentally ran at 350ppm NO3 (80ppm PO4) after a pump jammed on, with no fish and plant issues.

Generally mechanical issues with plants (eg pin holes) is either nibbling fish or poor CO2 for the light levels you are supplying.

 

[Akmaliano]

The reason why I started thinking of getting rid of excess NO3 is because apparently reducing it enhances the colour of red plants. How can one achieve that without making other plants suffer insufficient NO3?

 

[ian_m]

The reason why I started thinking of getting rid of excess NO3 is because apparently reducing it enhances the colour of red plants.

Never heard this myth before.

Well here is my red plants after 5 weeks whilst on holiday. Nitrate would have been through the roof due my EI autodoser.

Never had an issue get red plants to be red.

 

[Akmaliano]

Hi Ian, your plants do indeed look very nice and red.
Re the effect of limited nitrates on colour, I've come across this information on a few resources. The one I could remember was here:
https://www.aquaticplantcentral.com...etails.php?id=98&category=sci&spec=Limnophila

You'll notice in the middle of the second paragraph they mention about this. I also was surprised given that N is one of the main macro elements and how can its limiting be beneficial?

 

[ian_m]

I have never had problems with red plants when dosing EI. The picture below was supposed to be capturing the steam of oxygen bubbles coming from the plant, I get when lights are on, easy to see with eye, but difficult to photograph.

One issue to watch is the upper leaves clearly shade the lower leaves and get prone to "fading" and slight covering of BBA.

 

[Akmaliano]

Wow, that plant looks so healthy and bautiful. It's ludwigia isn't it? Love them.

 

[ian_m]

Wow, that plant looks so healthy and beautiful. It's ludwigia isn't it? Love them.

Can't remember what it was, but shortly after taking this picture, I squashed it during a water change/tank fiddle and this, the most colourful stem, never recovered and ended up fertilising the front lawn.