fish floating at the top after dosing fertiliser

[steve]

Hi guys,

My tank details:
3ft x 1.5 x 1.5.

last night, just change 50% water. dose 0.25 tsp KNO3, 0.25 tsp K2SO4,
2-3 rice grains of KH2PO4, 10ml of TMG.

this morning, saw all the fish floating at the top, even the shrimp is there.
do wc 50%, now is ok, but only dose 10ml of TMG. btw, thw CO2 is off.

Anyone knows the reason? K and PO4 is not harmful to the fish, right?
is it that I overdose the KNO3? but from chuck calculator, seems to be
ok.

[Sleepy_lancs]

If you never dose it before and suddenly bring stuff like KNO3 from 0 - 5 or 10. Your fish will just die of sudden change in environment. Try to bring your stuff 1 ppm per day... slowly.. no rapid changes.

[steve]

thanks, sleepy

maybe u r right. this is the first time that i'm dosing the compound
directly to the tank. For the previous WC, i mixed the
compound in a pail b4 putting into the tank.

thanks for ur prompt response.

[steve]

sorry, sleepy..

what u said applied to all compound, or only KNO3?

[theodore]

I doubt it has got to do with KNO3 if your dosage is accurate - 0.25 teaspoon (1 tsp = 5ml) -> 6ppm or so of NO3 ... not unless the concentration of NO3 is already at near harmful levels in the first place (>40ppm). Even if some of your citters get in contact with the undissolved salts, the effect (salt burn, stress, death) shouldn't be tank-wide.

How long has your tank been up? Did you use any water conditioners before your 50% wc? Btw, how often do you perform such a large wc? Did you do any major rescaping near the time of the 50% wc?

[Sleepy_lancs]

[quote:1db2a0b767="steve"]sorry, sleepy..

what u said applied to all compound, or only KNO3?[/quote:1db2a0b767]

I would apply it to all. Just to be on the safe side. But of coz. Do check your water parameters before adding stuff. Don't do it blindly.

[PeterGwee]

It has got nothing to do with the fertilizers I can tell you. Its something else...poor O2 or too much CO2.

Regards
Peter Gwee

[steve]

Hi all,

thanks for the views.

1.CO2 impossible, as the solenoid was not on at night, it was switched off
at 2200hrs.

2. I would do 50% wc every weekend, so it's a normal routine for me.
b4 wc, I would do all the pruning, re-landscaping etc. For the last
unevently wc, i did some minor re-lanscaping. Then, I do wc, add in
anti-chlorine, salt and fertilizer as per weekly after wc. Nothing special,
except, i dose the compound directly to the tank.

3. I did not do NO2, PO4 and K test b4 dosing, because after wc, I would
expect the level to be low.

rdgs,
steve

[steve]

sorry, addition to theodore:

the tank was 6mths old.

[tawauboy]

was co2 bubbling rate adjusted?
what are you using as ph buffer? baking soda?

[PeterGwee]

Steve, care to let us know at what time did you do the rescaping and then the water change? Personally, I would recommend you to do rescaping, uprooting jobs, prunning and water change in the early half of the lighting cycle if you can help it so that plants can still have the time to build up the amount of O2 for the critters and consume any ammonia being stir up from the upsetting of the substrate.

Regards
Peter Gwee

[steve]

the co2 was never adjusted.
currently, i don't have any pH buffer. Do i need that, and what is it for?

petergwee: mmm, i think my last wc is during the second half of the
light duration, abt 4 hrs to light off. will take note of that.


thanks.

[ckll]

Hey Steve, I think you've answered your own question. Since your wc was 4 hrs before lights off, you didnt give enough time for the plants to photosynthesize O2 during the 4 hrs.

At the same time, you probably pumped in Co2 which then caused Co2 poisoning. Hence you see the fish gasping for oxygen near the surface the next morning.

[Sleepy_lancs]

Any idea whats your KH level? With CO2 and critters, you need to ensure your water is having at buffering KH of least 3 or your poor critters be hit by a sudden PH swing when CO2 is injected.

[mkt]

there's been a spate of fish death related to water change lately.
possibly chlorine related....

[steve]

sleepy,

my kh is 3~4, i only used ceramic rings and cotton wool for filtration.
can ceramic rings used as kh buffer?

rdgs,
steve

[Sleepy_lancs]

[quote:8098e050a9="steve"]sleepy,

my kh is 3~4, i only used ceramic rings and cotton wool for filtration.
can ceramic rings used as kh buffer?

rdgs,
steve[/quote:8098e050a9]

Hi,

KH at 3-4 is okay. Try maintaining it around 4.

Ceramic rings can't be use as KH buffer. Coral chips or Calcium Carbonate tablet will be able to help you to increase KH. Bear in mind that regular water change is neccessary because both coral chips and calcium carbonate will keep increasing your KH.