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I tried to fishless cycle my 20 gallon tank last month. I started to get algae so I did not follow through with it. I did see a reduction in Ammonia but that might have been due to my plants. So of course, I ran out and bought some fish a few days ago. 4 Otocinclus, 2 junvenile Honey Gouramis and 1 juvenile Angel Fish.

3/12/21
• put fish in tank •

3/13/21
• 0.02 mg/l [NH3-N] •

3/14/21
• 0.05 mg/l [NH3-N] @bwc •
• 50% water change •
• 7.2 pH •
• 4.35 dGH Total Hardness •
• 40 mg/l CaCO3 Total Alkalinity •
• 26.9 mg/l CO2 •

3/15/21
• 7.2 pH •
• 360 mg/l tds •
• 0.02 mg/l [NH3-N] •
• dosed 1 5/8 tsp NaHCO3 •

1027253


My pH swings from 7.2 during the day when the Carbon Dioxide is running to 7.8 the next morning when the CO2 is off. That means NH3 has gotten (gotten is rotten) as high as 0.00165 ppm when the [NH3-N] was 0.05 ppm and the pH was 7.8 at 25° C. The EU limit is .005 ppm NH3. I expect the NH3 to get higher. I'm testing it everyday. It can go as high as 0.15 ppm [NH3-N] before hitting the EU limit.

"Fishlore.com post

The lethal dose for fish at about 1 mg/l ammonia (at 15° C), leading to suffocation with gill necrosis. For fish larvae are already 0.2 - 0.3 mg/l ammonia fatal. 0.03 to 0.05 mg/l ammonia lead to chronic damage, in which trout are particularly sensitive (Hütter 1990).
(The EU - guideline was 1978 ≤0.005 mg/l NH[SUB]3[/SUB])"

And then I came across this PDF:

"PDF from http://www.aztic.org/wp-content/upl...re-on-Ammonia-pH-Water-Temperature-v-2017.pdf

• In addition, you must always check, adjust and add KH alkalinity to maintain a minimum level of 100 to 150 ppm as KH is the primary energy requirement for the nitrification process. These ammonia removing nitrifying cultures require 7.1 pounds of KH alkalinity (carbonate alkalinity) for every pound of ammonia biologically removed in the nitrification process.
• If the KH level is depleted “nitrification will stop” just like a car running out of gas, and will not restart until KH levels are adequate.

Written by Chuck Dinkel, Maryland TIC and by D. Dent – Ecological Labs Inc."

Has anybody ever heard of this before? Do filters run better at a higher 5+ dKH? This is why I dumped the 1 5/8 teaspoons NaHCO3 into the tank to get the KH over 100 ppm. Do I need to increase my GH correspondingly? This hobby can be a real rabbit hole sometimes.
 

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That link does not work for me.

Nitrification also produces acid: NH4 + 2 O2 --> NO3 + H2O + 2H

Nitirification is pH-sensitive, with the optimum rate occurring at pH 8.3. At pH 7.0, the rate is 50% of maximum, and at pH 6.0 the rate is 10% of maximum. Alkalinity helps keep the pH at levels conducive to nitrification, but it is used up in the process. This is why we monitor our water chemistry and do regular water changes.

Source: Krenkel, P and V. Novotny. 1980. Water Quality Management. Academic Press, New York. 671 pp.
 

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Discussion Starter · #3 ·
Alkalinity helps keep the pH at levels conducive to nitrification, but it is used up in the process.
Yes, this is very interesting. I didn't even consider the effect pH has on nitrification. It's a good thing the pH is 7.8 at night. That means the Dinkel, et al. quote doesn't fully explain what's going on. The "gas" analogy isn't very strong.

Sorry about the link. The Planted Tank platform automatically linked that. I was just trying to quote it.
 

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It's not a very informative quote.

Did you ever add vinegar and baking soda and watch it bubble over? That's what is going on with nitrification, just slower. When you add an acid to a carbonate, you get CO2 and water i.e., HCO3 + H --> CO2 + H2O. The carbonate is used up and escapes to the atmosphere as CO2.
 

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Discussion Starter · #5 · (Edited)
It's not a very informative quote.

Did you ever add vinegar and baking soda and watch it bubble over? That's what is going on with nitrification, just slower. When you add an acid to a carbonate, you get CO2 and water i.e., HCO3 + H --> CO2 + H2O. The carbonate is used up and escapes to the atmosphere as CO2.
Well of course I have mixed vinegar with baking soda. What child hasn't indulged in that messy experiment? lol. That really does incapsulate what goes on in our aquaria.
Nitrification also produces acid: NH4 + 2 O2 --> NO3 + H2O + 2H
So the 2H is left over from the NH4 and causes an increase in acidity. Which lowers the pH slowing down nitrification. Sometimes the application of the basics gets lost on me. I remember seeing NH4 + 2 O2 --> NO3 + H2O + 2H in high school biology and not understanding it. I'm beginning to get it now because I'm worried about my new fish.

The Sodium Bicarbonate dump did increase the pH a couple of tenth points. Should I raise my 4.35 dGH up to match or exceed the KH?
 

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Actually, these interactions get a little tricky. NH3/NH4 briefly raises pH, but then turns around and reduces it by causing increased nitrification (the nitrification process increases acidity). We (me included) used to think that BB go dormant as pH approaches 6.0, but we have since learned that not only do BB that are normally adapted to alkaline water adapt to acidic water (although, it takes some time), but other varieties also appear to form at lower pH levels. I can’t provide links to these studies (you can Google for them), but Dennis Wong’s website has a link to one of them, here: 2Hr Aquarist Link

You also have to consider the accuracy of your test kits. Many kits, such as the API TAN (total ammonia kit) always, for me, read low-level ammonia when none exists. I’ve found the Salifert or Seachem kits to be more accurate. You can also get the Seachem “Ammonia Alert”, which will show only the free (deadly NH3) form of ammonia. Same problems go for pH readings. Pens are far more accurate than reagent tests, but do have to be calibrated correctly. So, make sure you are comfortable that what you see is what you have.

If you really believe you have dangerous levels of NH3 (know that plants suck this up fairly quickly), you can also add something like Prime to temporarily neutralize it. Many of us run, very successfully, with KH near or at zero. One of the interesting and important findings of the above reference study was:

“No difference in pH or oxygen microprofiles or in local conversion rates was found between biofilms grown on both materials. This similarity strongly supports our hypothesis that pH, within wide limits, does not primarily control growth and activity of nitrifiers. Our findings are in line with the observation that the increased addition of calcium carbonate to acidic tea soils does not affect nitrification rate.”

Keep in mind that carbonates begin to convert to CO2 when pH starts dropping below the 6.0 area. Nitrifying bacteria can use CO2, HCO3 or CO3 for their carbon needs.
 
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Discussion Starter · #7 ·
Actually, these interactions get a little tricky. NH3/NH4 briefly raises pH, but then turns around and reduces it by causing increased nitrification (the nitrification process increases acidity).
Mind blown. Somebody please come over and take this aquarium off my hands.
You also have to consider the accuracy of your test kits. Many kits, such as the API TAN (total ammonia kit) always, for me, read low-level ammonia when none exists.
I'm using LaMotte colorimeter. I think the tests are accurate because it was 0.02 ppm [NH3-N] the day after I put the fish in and then it went up to 0.05 ppm [NH3-N] the day after that. This is exactly what I would expect.
If you really believe you have dangerous levels of NH3 (know that plants suck this up fairly quickly), you can also add something like Prime to temporarily neutralize it. Many of us run, very successfully, with KH near or at zero...
The [NH3-N] can go up to 0.15 ppm at my temperature and pH. It can go as high as 0.30 ppm and still not be too bad. Good point about the plants going straight for the NH3. I was running low KH before I added the fish. But now I think the increased KH will accelerate nitrification.
“No difference in pH or oxygen microprofiles or in local conversion rates was found between biofilms grown on both materials. This similarity strongly supports our hypothesis that pH, within wide limits, does not primarily control growth and activity of nitrifiers. Our findings are in line with the observation that the increased addition of calcium carbonate to acidic tea soils does not affect nitrification rate.”
And the overall gist of your post. That higher KH does not affect nitrification and that BB adapt to different pHs.

Thank you Deanna.
 
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so.... just do whatever with your tank, as long as you keep doing the same thing it will become more or less stable. with parameters in reasonable values anyway.

or did I read this too fast.
 

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Discussion Starter · #9 ·
so.... just do whatever with your tank, as long as you keep doing the same thing it will become more or less stable. with parameters in reasonable values anyway.

or did I read this too fast.
Well, I'm thinking about keeping the KH up until the [NH3-N] goes down. Then I'll go back to dosing my 1 dKH Potassium Bicarbonate. I might put a sponge filter in a bucket with a heater, some Ammonia and bacteria to get a filter going faster.

So you're not buying this higher KH helping with nitrification either? I think we have a concensus developing here.
 

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Well, I'm thinking about keeping the KH up until the [NH3-N] goes down. Then I'll go back to dosing my 1 dKH Potassium Bicarbonate. I might put a sponge filter in a bucket with a heater, some Ammonia and bacteria to get a filter going faster.

So you're not buying this higher KH helping with nitrification either? I think we have a concensus developing here.
no, I was just interested and was trying to turn that all into a little synopsis.

My KH and GH are high enough naturally and I use tap with Prime. I wish it was softer, I just try to make sure the fish aren't too touchy about that. They all are doing well and that's all I care about.

I haven't gone this deep yet. Kinda actively trying not to. I appreciate that you guys have and are so I can reap the benefits from your conversations.
 
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