when does ammonia become toxic to plants - The Planted Tank Forum
 
LinkBack Thread Tools Display Modes
post #1 of 7 (permalink) Old 09-27-2007, 11:24 PM Thread Starter
Algae Grower
 
PTrader: (3/100%)
Join Date: Sep 2007
Location: DFW, TX
Posts: 67
when does ammonia become toxic to plants

at what ppm does ammonia become toxic to plants? Just curious.
midazolam is offline  
Sponsored Links
Advertisement
 
post #2 of 7 (permalink) Old 09-28-2007, 01:01 AM
Children Boogie
 
mistergreen's Avatar
 
PTrader: (13/100%)
Join Date: Dec 2006
Location: Cincinnati
Posts: 16,743
over 2 ppm i'm thinking. I remembered somebody having 4ppm of NH4 and their plants were melting.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
mistergreen is offline  
post #3 of 7 (permalink) Old 09-28-2007, 06:16 PM
Planted Tank Guru
 
plantbrain's Avatar
 
PTrader: (267/100%)
Join Date: Dec 2003
Location: The swamp
Posts: 13,609
http://www.springerlink.com/content/jth363558m0192w2/

and

http://www.pnas.org/cgi/content/full...f10f6db1750fd5

Directly from this and in direct contradiction with Diana Walstad's claim in her book:

"While one might expect NH4+ to be preferred by plants, as its assimilation requires less energy than that of NO3-, only a few species perform well when NH4+ is the only, or predominant, source of N. By contrast, most species develop toxicity symptoms when grown on moderate to high levels of NH4+ (1-6), whereas normal growth in these species is seen on NO3-."

When applying a routine to supply nutrients, it's likely best to suggest that mostly NO3 and a little NH4 from fish waste, perhaps decaying plant parts etc is the best solution.

There seems to be a temptation to assume there is "a preference" and it can be applied to all plants. There is no support for that speculation. the other issue left out oif the disccusion that you bring up is how much are we talking about?

0.1ppm? 0.5ppm? 1, 2, 5ppm?
What's safe for the other critters like fish and shrimp?
What about bottom fish that right next to the soils?

Further, if you consider the NH4 issue as far as rate of uptake specifically in aquatic plants, at less than 0.5ppm of NH4, NO3 uptake rate is faster in Elodea. If you use rate of uptake to suggest plant preference, then the answer is no, NO3 is preferred at less than 0.5ppm of NH4.
But preference is not merely defined to a few hours of uptake studies, you would also need to consider growth totals with various NH4 and NO3 ratios.
Grow things out for several weeks and take the relative growth rates from the dry weights.

So unless you plan on having rather high levels of very toxic NH4+(to fish let alone plants), this notion has some serious flaws in support.

The references for support should match the conclusion
That was not done.

So in answer to your question, yes, for many species, high levels will kill the plant, but other factors such as temp and pH play a role, as well as other ions present in the water to balance the internal ion charge and ability of the plants to balance those charges.

So it depends a lot on many things how much is required to kill plants, but high levels will certainly "harm" them(less growth, more respiration etc). Rice and some other plants can handle, or tolerate high levels, but it does not "help" them.

Regards,
Tom Barr




Regards,
Tom Barr
plantbrain is offline  
 
post #4 of 7 (permalink) Old 09-28-2007, 06:40 PM Thread Starter
Algae Grower
 
PTrader: (3/100%)
Join Date: Sep 2007
Location: DFW, TX
Posts: 67
Good to know!

I have a tank that I'm currently in the midst of a fishless filter cycle using NH3 that is at about 4 ppm. I was considering storing some plants in that tank but instead elected to set up a 10 gallon for some short term storage.
midazolam is offline  
post #5 of 7 (permalink) Old 09-28-2007, 10:26 PM
Planted Tank Guru
 
plantbrain's Avatar
 
PTrader: (267/100%)
Join Date: Dec 2003
Location: The swamp
Posts: 13,609
FYI, never use your tank to do some fool's method
Use a small bucket to cycle your filter, cheaper, easier and no testing needed.
Just start it up, add NH4, and a little dirt from outside, wait 3 weeks. That's it.

In planted tanks, FC is really not worth the effort to type even.
Plants use NH4 directly, come pre loaded with bacteria on roots/leaves etc, do not consume large amounts of O2(unless rotting).

There is no cycle in planted tanks because there are plants.
That's why they run healthier for fish and have little issue with NH4.

I suppose for fish only tanks for folks who do not live near anyone and have only one tank, FC may have some use, still, do the cycling in a bucket, never the tank.

Why add lots of NO2/NO3 which the NH4 will convert to and have to do a large water change?

In the bucket, you just dump afterwards, the tank is left alone.

Regards,
Tom Barr




Regards,
Tom Barr
plantbrain is offline  
post #6 of 7 (permalink) Old 09-28-2007, 10:29 PM
Guest
 
PTrader: (0/0%)
Join Date: Aug 2007
Posts: 169
That's a great idea which had never crossed my mind before, I'll have to remember that one.

On the topic, why do you have such high levels of ammonia? You only need a small amount to start cycling. Having such a high level will only, as Tom said, end up in all kinds of nitrates in your tank that you'll end up having to change out. More ammonia does not equal faster cycling.
Carissa is offline  
post #7 of 7 (permalink) Old 09-29-2007, 03:42 AM Thread Starter
Algae Grower
 
PTrader: (3/100%)
Join Date: Sep 2007
Location: DFW, TX
Posts: 67
Tom, thats a great idea. Buckets would be way cool. I just bought (a month ago) 4 tanks. One will be a quarantine tank, one a potential breeder and the other my show tank. I'm still researching, learning, etc. so I decided to start cycling filters in one of the two 40 gallons just so my wife would leave me alone about having 4 tanks with no water The bucket would be much easier and space saving.

Carissa, the NH3 is so high because I'm a newb and the article or two I read said 4 ppm was where it was at I can do a WC and bring it down though.
midazolam is offline  
Reply

Tags
None

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome