Decomposition Question

[SmallFish]

Hi guys,

May I know if dead plants/fish/shrimps in the tank will add on more Nitrates or Phosphates or Both or Others .. (ceteris paribus => all else in the tank remaining constant) ?

Thanks.
Joe

[vinz]

Actually not nitrates directly, but ammonia/ammonium. But in a stable mature tank, a tiny amount will be quickly converted to nitrites then to nitrates.

As for phosphate, I'm not too sure the processes, but I would imagine the answer is yes, but not in amounts that will make a huge difference to the tank.

Other elements will be released from the body too, but the question is what is the stable form they take?

[|squee|]

I'm sure that anything dead in the aquarium gives out ammonia, not nitrate or nitrite. Not sure if anything else gets out.

[eddyq]

If decay produce ammonia then it better to fish out anything dead, plant or fish because the tank is enclosed not some open lake or river where water is always moving.

[SmallFish]

Thanks bros for the responses.

This leads me to another question:
I often see dead leaves on the surface of my tank (it is a quite heavily planted matured tank) which I do nothing about most of the time.
Once a blue moon, a dead shrimp that I do not bother to extract.
How will this affect my EI standard dosage (especially NO3) if these decaying matters are left in the tank?
Or there is really nothing to worry about, since the ammonia given out is in very low/negligible amount?

I am just wondering if such decaying matters is one of the contributing factors for algae growth (despite all the EI, water circulation, optimised CO2 injection discussed extensively), since they do add chemicals like N (level of significance?) and could alter the water chemical composition.

[|squee|]

Yours is a heavily planted tank so any ammonia that gets in will be absorbed fast. If you read Diana Walstad's book, ammonia is the first thing plants look to for nitrogen, and the last thing they look to for nitrogen is nitrate.

I don't know about decaying matter contributing to algae growth despite good conditions.

[vinz]

Yes, take into context the size of the decaying material vs your water volume. a dead betta in a Horlicks bottle is a ammonia disaster area. As is 1 dead adult arowana in a 4ft tank.

Normal leaf death in a mature stable planted tank should not be an issue, provided you have good circulation in the tank. You may notice that algae often grow in areas of poor circulation.

[valice]

That's why you usually see algae growing in a moss pile while accumlated waste... The ammonia is a breeding ground for them...

[Plantbrain]

Test:

Take old plant cuttings

+

Stable tank

= algae

Like fish waste, plants decompose into NH4 as well.
Compost.......

It's a fairly simple test.


Regards,
Tom Barr

[SmallFish]

Thanks all for your feedback / advice.

I guess some of you might have noticed that I did not mention water change. Yup, guess I need to religiously change 50% per week to 'reset' the system.
On a 7 days cycle, such 'normal' decomposition should not be a cause to worry, i surmise.