• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up
  • You can now follow UKAPS on Instagram.

Dark Start, Ammonia and Ammonium

Djoko Sauza

Member
Joined
23 Jul 2017
Messages
253
Location
SE London
Fragile in-vitro and generally vulnerable plants are prone to melting at startup due to the excessive levels of ammonia released from the substrate when using new aquasoil. Dark Start is a way to start up your aquarium with a more balanced and mature ecosystem, thus preventing plant melt and algae growth.
There are enough threads explaining the process but it's basically leaving the tank to its own devices for the first weeks with nothing but substrate, harscape and a running filter. The aquarium should also be blacked out and water changes are optional.

Now to the point. If all the usual startup problems are caused by excess amonia, would lowering the water pH, turning ammonia into ammonium, solve the issue?

Or are plants as sensitive to ammonium as they are to ammonia?

Which pH would be low enough in order to have a negligible amount of ammonia present?

Thanks
 

ceg4048

Expert/Global Moderator
UKAPS Team
Joined
11 Jul 2007
Messages
9,598
Location
Chicago, USA
Now to the point. If all the usual startup problems are caused by excess amonia, would lowering the water pH, turning ammonia into ammonium, solve the issue?
Hello,
It's not as simple as just lowering the pH. In toxicology a general rule is that the concentration determines toxicity. The majority of folks using Aquasoil are also using CO2, which does lower the pH and they may still suffer toxicity as there is a LOT of NH4. In any case, the issue with NH4 is not so much that it damages the plant but that it triggers algal blooms which can then damage the plants. Also, regardless of the number of threads, what many hobbyists think is damage due to NH3/NH4 is actually damage due to poor CO2, something that's rarely discussed in this context because there is a mindset that their CO2 is good, so their problem must be NH3. For the record, I use Aquasoil many times with in-vitro plants and rarely have this issue. The water change schedule needs to be robust however.

Which pH would be low enough in order to have a negligible amount of ammonia present?
Here is a typical NH4/NH3 equilibrium chart showing that at a little over pH 6.5 most of the N is in NH4. There is an effect of temperature also however.
Relationship-between-the-ammonia-ammonium-NH-3-NH-4-ratio-and-pH.png


Dark Start is a way to start up your aquarium with a more balanced and mature ecosystem, thus preventing plant melt and algae growth.
Yes, we're familiar with the dark start but there is an easier way, called mineralization, where it's a very simple procedure to oxidize the NH3/NH4 to NO3 by simply baking the Aquasoil in an oven at say, 400 deg.F for about an hour. Let it cool and it will be fine to use. Yes, you can do the dark start as that will allow time for bacterial colonies to get a better population.

are plants as sensitive to ammonium as they are to ammonia
As I mentioned, NH3 can be extremely toxic, even to those organisms that process NH3 to NO2. Mineralizing the Aquasoil by baking is the best policy as it provides NO3, which plants love.

Cheers,
 

Djoko Sauza

Member
Thread starter
Joined
23 Jul 2017
Messages
253
Location
SE London
Thanks for the detailed reply. I suspected it wouldn't be as simple as lowering the pH.

Just hypothetically, what would happen if you'd lower it to some ridiculous value like say 4?

Yes, we're familiar with the dark start but there is an easier way, called mineralization, where it's a very simple procedure to oxidize the NH3/NH4 to NO3 by simply baking the Aquasoil in an oven at say, 400 deg.F for about an hour. Let it cool and it will be fine to use.
To be honest I never heard of this method, I wonder if anyone else here uses it? Perhaps since it's expensive stuff noone is willing to just throw it in the oven like that, even if it would be beneficial.

Yes, you can do the dark start as that will allow time for bacterial colonies to get a better population.
Indeed, dark start is probably still the best way to achieve a more mature substrate before having the tank running proper.

It seems like if the goal is to prevent algae, the simple solution would be to start with lower light levels. At the same time some here start their tanks with lights at full blast and have few algae problems. But to be fair their water changes and husbandry are usually on point.
 

Angus

Member
Joined
29 Aug 2008
Messages
655
Location
Vauxhall, London.
Yes, we're familiar with the dark start but there is an easier way, called mineralization, where it's a very simple procedure to oxidize the NH3/NH4 to NO3 by simply baking the Aquasoil in an oven at say, 400 deg.F for about an hour. Let it cool and it will be fine to use. Yes, you can do the dark start as that will allow time for bacterial colonies to get a better population.


As I mentioned, NH3 can be extremely toxic, even to those organisms that process NH3 to NO2. Mineralizing the Aquasoil by baking is the best policy as it provides NO3, which plants love.
Hi ceg, curious how this works, so as aquasoil is kiln dried at around say 190 degrees F, it is not subject to the oxidation process during manufacturing? is this why certain aquasoils are considered ammonia free? because they are baked in kilns that run at a higher temperature?
 

dw1305

Expert
UKAPS Team
Joined
7 Apr 2008
Messages
13,706
Location
nr Bath
Hi all,
it is not subject to the oxidation process during manufacturing? is this why certain aquasoils are considered ammonia free? because they are baked in kilns that run at a higher temperature?
I'd guess they add the ammonia <"after calcining">.
because they are baked in kilns that run at a higher temperature?
If you baked the soil in a <"very hot oven"> it would be nearer to inert.

cheers Darrel
 

Angus

Member
Joined
29 Aug 2008
Messages
655
Location
Vauxhall, London.
Hi all,

I'd guess they add the ammonia <"after calcining">.

If you baked the soil in a <"very hot oven"> it would be nearer to inert.

cheers Darrel
So they are adding nutrients via a soak/shower process and drying afterwards? i have heard of calcination kilns but i thought those ran at far higher temps, that's why i assumed aquasoil would be kiln dried clays, but you are saying it is calcinated soils? all very interesting to me, you guys definitely have the knowledge.
 

dw1305

Expert
UKAPS Team
Joined
7 Apr 2008
Messages
13,706
Location
nr Bath

jaypeecee

Member
Joined
21 Jan 2015
Messages
2,608
Location
Bracknell
Fragile in-vitro and generally vulnerable plants are prone to melting at startup due to the excessive levels of ammonia released from the substrate when using new aquasoil.
Hi @Diogo Sousa

I'm interested but have not been able to find very much on the internet about this - with the exception of what's on YouTube. Do you have any links that you would recommend?

JPC
 

Wookii

Member
Joined
13 Nov 2019
Messages
3,046
Location
Nottingham
So they are adding nutrients via a soak/shower process and drying afterwards? i have heard of calcination kilns but i thought those ran at far higher temps, that's why i assumed aquasoil would be kiln dried clays, but you are saying it is calcinated soils? all very interesting to me, you guys definitely have the knowledge.
Hi all,

That would be my guess.

I think it is quite soft, so kiln (or air dried) would be my thought. If I was a betting man I'd bet on something <"very close to this process">.

cheers Darrel

That is interesting. It's a shame they choose to use ammonia rather than some other, less toxic source of N.
 

ceg4048

Expert/Global Moderator
UKAPS Team
Joined
11 Jul 2007
Messages
9,598
Location
Chicago, USA
Just hypothetically, what would happen if you'd lower it to some ridiculous value like say 4?
Well, nothing drastic will happen. That will still be below the crossover point as shown on the chart, so most or all will be NH4.
Hi ceg, curious how this works, so as aquasoil is kiln dried at around say 190 degrees F, it is not subject to the oxidation process during manufacturing?
That is correct. The soft clay pellets are soaked in a nutrient solution. In order to mineralize the NH3/NH4 to NO3 the oven needs to be around 400 degrees.F. for approximately an hour.
It's a shame they choose to use ammonia rather than some other, less toxic source of N.
NH4 is cheap and delivers 4X the Nitrogen per unit weight than NO3.

Cheer,
 
Top