Pond testing

[cr8tivguy]

Hi everyone.
I got my mac-daddy test kit yesterday and did an initial test for my tap water.
Everything reads pretty normal:
PH 9
Ammonia 0
Nitrate 0
Phosphate 0

When I tested my pond water I got:
PH 7.5
Ammonia 1 (just fed the fish maybe 20 minutes before the reading)
Nitrate 0
Phosphate 1

I'm going to run tests daily for a while so I can get accustom to reading the tests and chart the results in a spreadsheet.

The next reading I'm going to do before food and then after (20 minutes) so I can get a good understanding of how feeding impacts the water quality.

Sound like a good idea?
Tim

 

[crsublette]

Definitely imporant to know the KH values as well, as is explained in the hyperlinks I have shared with ya.


I would be very careful about the ammonia presence. Eventhough it is beneficial to the pond's bio-filter to grow faster, the ammonia presence can hurt the fish. Although, I know goldfish and koi carp are extremely hardy. These fish can survive, not necessarily thrive, in quite high ammonia levels. One particular koi breeder and professional retailer would go as far to say they can survive up until the concentration of the ammonia (NH3) reaches 1 ppm, but they may not survive this without significant harm for an extended period.

So, this leads into the conversation discussing the differences between ammonia (NH3) and ammonium (NH4+). Ammonia (NH3), also called "free ammonia", is extremely toxic, although not as toxic as nitrites, to fish. An ionic law of chemistry and equilibria state that ammonia and ammonium must remain in balance to match the enveloping environment. When the fish excretes ammonia (NH3) through their gills, excreta, and respiration, this ammonia instantly begins to dissolve and absorb into the water by stripping a hydrogen cation (H+) away from water. Remember, water (H2O) is made from one hydrogen cation (H+) and one hydroxide anion (OH-). So, during this process, a portion of the ammonia strips that cation away from water and creates ammonium (NH4+) and a hydroxide (OH-). As mentioned in my previous hyperlinks, as the hydroxide (OH-) increases, then so does the pH. However, since in our context, there are many other contaminants, such as salinity, temperature, pressure, gases, etc, in the pond water that cause another reaction. When the pH increases, another reaction is created to strip a hydrogen cation (H+) away from NH4+ causing the creation of more ammonia (NH3). So, as the pH and temperature increases, then this ammonia-ammonium equilibrium relationship favors the formation of the toxic ammonia.


Here is a calculator to help you determine your ammonia (NH3) concentrations. CNYKOI - Total Ammonia calculator.


Lets critically apply your testing parameters with this total ammonia calculator to determine your toxic ammonia (NH3) concentration and lets assume the water is 78*F.

7.0 pH, 78*F, 1ppm total ammonia = approximately 0.006 ppm of NH3

7.5 pH, 78*F, 1ppm total ammonia = approximately 0.019 ppm of NH3

8.5 pH, 78*F, 1ppm total ammonia = approximately 0.16 ppm of NH3

9.0 pH, 78*F, 1ppm total ammonia = approximately 0.372 ppm of NH3

Now... with an increase water temperature...

7.5 pH, 78*F, 1ppm total ammonia = approximately 0.025 ppm of NH3

9.0 pH, 86*F, 1ppm total ammonia = approximately 0.446 ppm of NH3


So, it is a judgement call. If the 1 ppm ammonia is soon reduced by your plants or machanized bio-filtration, then it is no problem as long as your pond's pH and water temperature is not changing too much, throughout the day, causing the creation of the toxic ammonia.

 

[cr8tivguy]

Just did another test with my liquid test kit:
PH 5
AMMONIA: .25
NITRITE: 2
PHOSPHATE: .5
dKH: 2
GH/KH: 35.8

Big drop in the PH level from 7.5 yesterday. Not sure what would cause this. There was no water change. Ammonia dropped (this test was done before feeding). And the Nitrite level is now at 2 up from 0. My water seems a bit soft based on the hardness chart.

My 5-in-1 test strip shows
Nitrate: Safe
Nitrite: 1.0 (stress)
Hardness: 300 (very hard)
Alkalinity: 40 (low)
PH: 7.2 (acceptable)

Should I be concerned about the drop in PH yet? The fish are doing fine. I watched them for a good 15 minutes and they are swimming around as usual.
Tim

 

[sissy]

I use crushed oyster shells from tractor supply to stabilize ph and I only feed 3 or 4 times a week .

 

[cr8tivguy]

Thanks Sissy! I'm heading to Tractor Supply right away. I also read about Baking Soda in the water will bring up PH. Should I try that first?

 

[HTH]

I would rather leave this to someone who has experiance with pond pH crashes.

 

[cr8tivguy]

thanks

 

[sissy]

I just tested mine today as last night we had really heavy heavy rains,Crushed oyster shells still doing there job.Filters and plants helping

 

[cr8tivguy]

I tested this morning. My PH is back up to 8 and my KH is hard (thanks Oyster Shells). I did a small water change (about 50 gallons) and tested an hour later.
The PH stayed at 8 and the KH dropped a bit (not much). I removed the Oyster Shells because I wasn't sure if these need to remain in the water all the time or only when the water hardness drops.

Sissy, do the oyster shells stay in all the time? Oh and Tractor Supply had a 50 lb bag for 10 bucks! I used a black pillow case for the material because the shells were crushed and kind of powdery.

 

[HTH]

I am not sissy but I can provide the answer if you like.

Leave the shells in. They will not cause any problems like raising the pH too high.

 

[cr8tivguy]

GREAT! Thanks Howard.
So I shouldn't be too concerned about the water getting too hard (if there is such a thing)?

 

[sissy]

I have been using them I think over 4 years all year round ,never a problem yet .Oyster shell just stabilize ph .I use pdz horse stall refresher to help with ammonia also .Dollar store laundry bags doubled up work great
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[HTH]

I am not sure if this is the right analogy but I think of the shells like salt. Only some much of it will go into solution. As it is used up more can dissolve. Maybe Charles can comment on this.

Sissy my wife is out shopping and with some luck I should have some PDZ when she returns. I plan to put some in each of the tubs the baby fish are in. Trying to decide if I should put it in a mesh bag in the tub or load a bubble up filter with it. I still do not have a good feel for how large it is. I should by tonight And thanks for that hint.

 

[crsublette]

Tim, what is the alkalinity, in dKH or ppm, of your tap water ??



Almost like salt in that particular sense. However, salt leaves residual elements in the water that is not true with a calcium carbonate product, such as oyster shells.

Bicarbonate, which is also measured in the KH value, is the carbon energy source for bacteria and algae and other aquatic plants. As the bacteria and these plants thrive, bicarbonate is consumed. If your water's carbon dioxide level is low and algae presence increases, then the algae will consume even a higher level of bicarbonate than usual due to the fact of algae reducing bicarbonate (HCO3) into carbon dioxide (CO2) and a hydroxide (OH-). As ammonia and carbon dioxide maintains an equilibrium in water, then some bicarbonate is consumed as well. Also, any dilution of the water with an acidic source, such as rain, or other contanimants will also consume the bicarbonate.

So, bicarbonate, which is what we are in particular assuming when measuring KH, will be depleted and the processes involved above are allowing the pH swings you have experienced.

As far as oyster shell, it is a stabilizer product, but it is not like baking soda, which is much more fast acting. Do not be surprised if your pond is in the situation where the oyster shell does not fix the problem. So, it might need to be supplemented with some baking soda. For more explanation on oyster shell, that is a calcium carbonate product, then read: Ph Fluxuation? How to control? and Low GH and KH! What to do?.

In regards to Sissy's and Addy's and other's situation that have only ever used oyster shells to stabilize the pH, I am expecting the oyster shell is allowing the water pH reach its "natural" level, that is matching its environment. "Natural" in that it is the particular correlation point met when the oyster shell product can only dissolve so fast to meet a particular consumption created by the environment.

 

[sissy]

don't know much about fish tanks but hope it works it is fine