[roundar]

Forgive me if any of my terminology is wrong, I'm certainly not a chemist. In the aquarist hobby it's common to treat tap water with products such as Prime that, according to the label "Removes Chlorine, Chloramines, and Ammonia."  I've recently begun breeding fish (while attending school) to educate myself in many area's including chemistry, I'm looking for ways to get rid of products like prime, and do these things myself.  I recently acquired Sodium Thiosulfate which will dechlorinate tap water, but I still want to find something that will convert toxic ammonia into non toxic(at these levels for aquatic life) ammonium.  Because products like the one I mentioned are time tested, I have to assume I can accomplish this via introduction of some chemical.  Any help on determining how to do this would be greatly appreciated.

EDIT:  If I can be more specific or give any more information I'd be happy to.  Even if there isn't a simple answer to my question, any information on the subject would be very interesting to me.

[roundar]

No thoughts?  Perhaps this is the wrong forum?  I hope someone will move it if that's the case.

[enahs]

In low pH water NH3 goes to NH4+ anyway.

[roundar]

I'm familiar with that.  I doubt anyone here is particularly interested in it, but I'll post this: http://dataguru.org/misc/aquarium/AmmoniaTox.html  But sometimes it's good to have something that will detoxify ammonia, particularly before the nitrogen cycle completes in a tank. In addition, if your tap water has a higher PH it's generally more beneficial to maintain a high PH than to have PH constantly changing.

[typhoon2028]

If you have established water chemistry.  Ammonia should not build up.  It will be eliminated by bacteria throught the nitrogen cycle.

Ammonia can spike if fish get stressed or you introduce to many fish into a small water volume.

Chemically removing ammonia is difficult, thats why you you want the bacteria to do it for you.

You indicated that it is more beneficial to maintain a higher pH.  Higher and lower are relative.  And this would depend on the fish type.  In acidic conditions ammonia, NH3, will convert to more ammonium ion, NH4+.  NH3 is highly toxic to fish.  Ammonium is safer.  But in an alkaline fish tank, less ammonium will exist and will begin to form NH3.

You can aerate the tank to help remove excess ammonia.

[roundar]

If you have established water chemistry.  Ammonia should not build up.  It will be eliminated by bacteria throught the nitrogen cycle.

Ammonia can spike if fish get stressed or you introduce to many fish into a small water volume.

Chemically removing ammonia is difficult, thats why you you want the bacteria to do it for you.

You indicated that it is more beneficial to maintain a higher pH.  Higher and lower are relative.  And this would depend on the fish type.  In acidic conditions ammonia, NH3, will convert to more ammonium ion, NH4+.  NH3 is highly toxic to fish.  Ammonium is safer.  But in an alkaline fish tank, less ammonium will exist and will begin to form NH3.

You can aerate the tank to help remove excess ammonia.  

Thanks for your response.  I only suggest that it's beneficial to maintain higher PH if in fact that is the PH of your tap after aeration since lowering it would only  be temporary and would cause constant fluctuations.  As I said, the nitrogen cycle will take care of ammonia, but this only true in an established tank.  Also, as indicated by my previous post, I fully understand the relationship between pH and ammonia/ammonium.

Removing ammonia, or more accurately in this case, converting free ammonia into ammonium, may be difficult but is possible chemically.  Many products can do this, and I'm trying to pinpoint how.

[zaphraud]

If this is going in a small fish tank, just heat the water to boiling, pour it into a large metal bowl, freeze the water solid in the freezer overnight, then remove the very large chunk of ice. Smash it up, and quickly rinse the ice cubes in a colander, shake them dry and allow them to melt down into a bowl.

Boiling drives off chlorine and chloramine quite effectively. Ammonia shouldn't be an issue in tap water in the first place, but boiling drives it off too.

Smashing fractures the ice preferentially along crystal defects - where impurities are concentrated. In theory, all of these are water soluble in the first place. In reality, tiny chunks of calcium carbonate probably precipitate that don't really redissolve too well, but they sure rinse off nicely.

The slow melt dripping into a bowl allows the water some time to reabsorb oxygen from the air.

Chances are doing this in the home uses more energy or your utility bill than a gallon of distilled water would cost at the store, but if you avoid plastic the results are tastier for some people. This wont remove all of everything, but its relatively simple and uses only what most people already own equipment wise.

[roundar]

It's not a small tank. It's about 30 tanks and using RO/DI water without supplementing it with minerals/salts will kill fish.  The ammonia is produced by fish, feces and any uneaten food.  In breeding tanks it's not going to be the case that one can always depend on the nitrogen cycle as tanks are added/removed/changed.  The usual solution is to replace 50% or so of the water to keep the ammo levels down. After aeration my tap water has a pH of roughly 8.2.  Even the low levels of ammonia we're talking about (about .25-.5ppm) are toxic.  I'm looking for a way to chemically change the free ammonia into ammonium.

[zaphraud]

It's not a small tank. It's about 30 tanks and using RO/DI water without supplementing it with minerals/salts will kill fish.  The ammonia is produced by fish, feces and any uneaten food.  In breeding tanks it's not going to be the case that one can always depend on the nitrogen cycle as tanks are added/removed/changed.  The usual solution is to replace 50% or so of the water to keep the ammo levels down. After aeration my tap water has a pH of roughly 8.2.  Even the low levels of ammonia we're talking about (about .25-.5ppm) are toxic.  I'm looking for a way to chemically change the free ammonia into ammonium.

Forcing a large amount of the mineral content out of water with a freeze/remelt will definitely give you a different pH after what I was describing is done; the water is far less hard afterwards, and the near 0c drip-down will give it a lot better interaction with the gasses in the air than the aeration you get from a simple screen in the tap itself, but somehow I have a feeling this still doesn't solve your problem.

Inititally, I was thinking you just needed to get rid of the chloramine or the chlorine that makes it when it comes into contact with biological wastes; but now it sounds like you are also looking to make sure the water has enough of something else in it that it can act as a buffer - by keeping the pH neutral, the vast majority of the nitrogen will be present as ammonium. So now I ask you, what ionic substances are non-toxic to these fish and at what levels?

[roundar]

I appreciate your replies. Indeed, freezing >300 gallons of water a week is not a cost efficient option.  When I say my pH iss 8.2 aerated, I mean to say that it is at 8.2 after standing 24 hours with air being pumped into it.  I'm getting rid of the of the chlorine/chloramines with sodium thiosulfate.  The free ammonia concentration needs to remain below .1mg/L, and the pH needs to remain at 8.0-8.2. (Almost all aquatic life will adjust to various pH levels, but I need it to stay in this range because it creates the optimum breeding environment for these species.)

[zaphraud]

Oh sorry about the aeration error - I guess I know too little about fish compared to plumbing and got stuck in the mentality of water from the tap. My mistake.


If there's too much ammonia, and you can't change the pH to be less basic, you're going to have to keep the ammonium out too. If you are holding pH at a constant already and there is too much ammonia, there's also too much ammonium... the pH more or less dictates what the relationship between the concentration of the two is going to be; temperature and some other stuff has effects too, but.. it looks like you just need to get the amine concentration down overall. Driving it out with aeration is one method for sure, as long as the tank is in a ventilated area, otherwise you just end up driving it back in, eventually - not to mention making the place smell really stinky. 

Really though, its starting to look like your cheapest option is to add plants of some type (no idea but I have a hunch aquarium buffs would know the species to use), with the appropriate lighting, the pet store nearby has a really nice setup where the water-processing plants are in a different tank that drains into the tank with the fish in it in a rather ornamental manner. Plus, they usually smell a whole lot better than any of the other alternatives, chemical or bacteriological. Plants thrive on natural amounts of amines in water, and root systems are a great membrane-based solution that never needs replacing :-)

[roundar]

Lol, yeah I have a couple planted tanks.  There's going to be some plants in these later for fry cover which will readily feed on the ammo like you said.  The interesting thing is that as far as aquatic life, ammonium is virtually non toxic, and somehow certain products have long since proven themselves capable of converting the ammonia with negligible impact on pH.  The length of time they do this is debated however.  One option is zeolite in my filtration which won't rid the tank of ammonia, but will at least hold it.  I'm just growing more and more curious how it's done chemically.  Thanks for your help

[shimy]

It's very simple.
attention :
NH3  +   HCl ---->  NH4+Cl-

[zaphraud]

It's very simple.
attention :
NH3  +   HCl ---->  NH4+Cl-

That would produce a significant change in the pH; apparently these fish like things kept slightly basic.

[smarter]

My opinion is according to my best friend Shimy.
pH of this test doesn't change. because Halids always are  Neutral.