Low NO3

[theodore]

My 2ft tank now has :

6x Golden Pencil
6x Rocket-tail Pencil
6x Dwarf Pencil
6x Oto
3x Golden Ram
3x Guppy

I would consider 30 fishes a sizable population (in a 2ft tank) but my NO3 is between 0-5ppm (Sera testkit)! NO3 was between 12.5-25ppm abt 1 month ago (my friend's Tetra testkit). My plants have yet to show any N deficiency but I have stopped my CO2 tonight cos pH=6.4 KH=6 => CO2=71mg/l !!!

What r my best options (NO3, add fish, feed more, etc)???

[PeterGwee]

First of all, is your CO2 pressurised type or DIY? If it is pressurised type, you need to set the bubble rate properly when you can stay at home for the full day..(takes time to set properly and problems come so fast and deadly when you screw up so make sure you are there when your fishes need you ). As for NO3, you will need to know much about PO4 level before deciding what to do next...it takes a complete set of nutrients for plants to uptake at a fast rate...(NO3,PO4,Potassium,Fe,Traces,CO2)

[bclee]

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On 4/3/2003 12:27:16 AM

My 2ft tank now has :

6x Golden Pencil
6x Rocket-tail Pencil
6x Dwarf Pencil
6x Oto
3x Golden Ram
3x Guppy

I would consider 30 fishes a sizable population (in a 2ft tank) but my NO3 is between 0-5ppm (Sera testkit)! NO3 was between 12.5-25ppm abt 1 month ago (my friend's Tetra testkit).
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That is not surprising. What lighting wattage are you using?
With high lighting & CO2 injection, plants will be taking up nutrients pretty fast.
You may consider adding NO3 to raise the level to 5~10ppm.

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My plants have yet to show any N deficiency but I have stopped my CO2 tonight cos pH=6.4 KH=6 => CO2=71mg/l !!!
----------------

You may get algae infestation first before clear signs of N deficiency. But if you dose NO3 you may see the difference. You may find your plants turning greener.

I really doubt your pH/KH reading. If your fishes are not struggling, you don't have to cut the CO2. Double check your readings.

BTW, are you adding any buffers to your tank other than KH up or baking soda?

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What r my best options (NO3, add fish, feed more, etc)???
----------------

Don't feed more, you may foul up the water.

Too many fishes will cause stress and affects fish health.

Fishes and rotting food/fish poo produces NH3. NH3 is said to be prefered by algae.

BC

[theodore]

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First of all, is your CO2 pressurised type or DIY? If it is pressurised type, you need to set the bubble rate properly when you can stay at home for the full day..(takes time to set properly and problems come so fast and deadly when you screw up so make sure you are there when your fishes need you ).

I'm using pressured type, manual regulator. I usually set it to 3 bubbles/sec (when i reset it) and it would slow down to 2 bubbles/sec after 24hrs (yah, i know my cheap taiwanese regulator is a bit koyak).

As for NO3, you will need to know much about PO4 level before deciding what to do next...it takes a complete set of nutrients for plants to uptake at a fast rate...(NO3,PO4,Potassium,Fe,Traces,CO2)

Damn, need to allocate budget for 1 more testkit now. so far I only have pH, KH and (recently bought) NO3.

Oh...one more thing..you mention that your CO2 level was 71ppm or mg/l...??? Are your fishes okay when you measure 71ppm or mg/l of CO2? If not, I think either your pH or KH reading is skewed. Can you tell me what test kit you are using? pH test kit or test pen?..For KH test, take double the amount of tank water sample (etc. 5ml as instructed by manual but take 10ml instead) then find the number of drops it takes to change from blue to orange. Then divide the number of drops by 2. A much precise reading would be measured.
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I'm using Sera for both pH and KH. 6.4 should be a very close estimate cos the colour is just slightly off the one given for 6.5. I have already redone the KH test last night using the 2x method after my posting (too worried, cant sleep) and i got 5.5 this time.

With my new values (6.4, 5.5), i have (59+71)/2=65mg/l. This is still too high and yes, my a number of my fishes do have redder than usual gills (esp. my dwarf pencils and otos). The surprising thing is that my shrimps seems to be surviving well (only 1 casualty after I added 30 Malayans on Sun).

[bclee]

Signs of CO2 poisoning is when fishes comes up to the surface breathing heavily. If they are not doing that, it is unlikely that your CO2 is that high.

Again, did you add any pH buffers or the like? What do you add to the water.

BC

[PeterGwee]

I have used Sera pH test kits before...they are not bad but just not precise enough I guess. The range is too wide...example..6.0,6.5,7.0 and etc...what if the pH is actually 6.8? What do you read then? If you have the money, go and get yourself a pH test pen...if not..maybe you can ask a kind forumer to go to your house to test for you during the weekend []

[theodore]

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That is not surprising. What lighting wattage are you using?
With high lighting & CO2 injection, plants will be taking up nutrients pretty fast.
You may consider adding NO3 to raise the level to 5~10ppm.
----------------

2x36W PL

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You may get algae infestation first before clear signs of N deficiency. But if you dose NO3 you may see the difference. You may find your plants turning greener.
----------------

What kinds of algae usually crop up when N is limited? So far, I have green brush algae on driftwood and hair algae on (and in) my moss.

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BTW, are you adding any buffers to your tank other than KH up or baking soda?
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Just backing soda every water change.

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Don't feed more, you may foul up the water.
Too many fishes will cause stress and affects fish health.
Fishes and rotting food/fish poo produces NH3. NH3 is said to be prefered by algae.
----------------

What if i start dosing KNO3 and my P gets limited (K shoudn't be an issue cos I dose K2SO4)? Add KH2PO4 then? Aiyoh ... []

[juggler]

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On 4/3/2003 12:27:16 AM

my NO3 is between 0-5ppm (Sera testkit)! NO3 was between 12.5-25ppm abt 1 month ago (my friend's Tetra testkit). My plants have yet to show any N deficiency
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Just in case you did not test correctly using the Sera NO3 test. Did you wait 5 minutes (as instructed in the directions) before reading the results?

[theodore]

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Just in case you did not test correctly using the Sera NO3 test. Did you wait 5 minutes (as instructed in the directions) before reading the results?
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Yup, i did wait 5min before comparing the solution to the given colour charts.

Riccia pearling have reduced in intensity (and speed). I also found a small (2mmx2mm) hole on an adult leaf for my lace plant - Dunno if the hole is caused by deficiency or fishes/shrimps/snails.