Yet Another Fishless Cycle Question!

Electric Warrior

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Hi all. I am fishless cycling a 200L tank with ammonia using the "add and wait" method. My Nitrite readings are still off the chart, and today for the first time, I got a Nitrate reading, also off the chart - deep red (API kit). I also decided to check my PH and it has dropped significantly: it's been sitting at about 7.4, and today the reading is at about 6.4~6.6??? Can this be right? Obviously this change coincided with the nitrate appearing today, so I was wondering if this had something to do with it? In theory, this PH level is fine with me because I was wanting to keep acidic water fish, but I was wondering if such a massive fluctuation is normal?
 

the_lock_man

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In terms of fishless cycling, it happens very often, and it can cause your cycle to stall - the bacteria don't like to grow in that pH. I would suggest you get some bicarbonate of soda, and add it bit-by-bit until your pH hits around 8.0-8.2. I can't remember the exact science, but the nitrite or nitrate converts into nitric acid, and therefore turns the water very acidic. You need to keep an eye on the pH in case it happens again.

When the cycle finishes, you'll do a huge water change (to get rid of the nitrate) and your natural pH will return.
 

TwoTankAmin

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Before adding baking soda, do a 50% water change to get the numbers down and the pH back up. If that fails then consider adding the baking soda. the thing is cycling for low pH is a long process and starting out at 8+ will make it even longer and more work.

If you want to get a tank cycled for acid water fish it will take much longer than a normal cycle. You first need to get the tank cycled at a neutral pH or close to it (which is why 8+ is to be avoided now if possible). Then you need to gradually work this down to your desired level by moving in .2 pH drops. Each drop will cause bacteria to die off, but some will survive and you need to get these survivors to multiply until you are again cycled at the lower pH. Once the tank is again fully oxidizing ammonia etc., you can drop it .2 again and repeat the process.

Each step can take 2-4 weeks to complete. You may need either a special low range pH test kit or even need to get a pH meter as most test kits wont work below 6.0 and I am not sure how reliable they are as they approach 6.0.

The one plus is at pH 6.0, ammonia is pretty much not an issue as it will be all NH4 and no NH3. 8ppm of total ammonia at a pH of 6.5 and a temp of 85F will translate to .02 ppm of NH3 (a reading of between.03 and .05 is considered to be where problems begin to occur.)
 
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Electric Warrior

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Okay, I just double checked PH and it's def at about 6.6. So are you guys saying that this level is def too low to keep cycling the tank, without having to do a big water change, add things, etc.? And why does this actually occur for some?
 
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Electric Warrior

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Okay, so I haven't done a wc yet, and I wanted to see what would happen after another day or so, so I just tested and PH is now at 6.4. I dosed about 3.5ppm of ammonia yesterday, because it was at zero, and it was at zero again just now, 24 hours later. It has been dropping back to zero within 24 hours the last 3 or 4 days. My nitrites are still off the chart, but nitrates just read about 5ppm after seeming to be at about 80ppm yesterday. Any thoughts as to where this is heading? I understand that the 6.4-6.8 ph range isn't optimal for a cycle, but I am slightly wearing of screwing things up, since everything else seems to be going pretty normal (I think?).
 

jb1997mcd

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You are now waiting for your bacteria to develop to take down the nitrites and produce nitrates. For me this part of the fishless cycle always is quicker than the intial part of getting the ammonia down to zero.

I am really not sure how your nitrates went from 80ppm to 5ppm overnight. Provided the water you are using does not have a high level of nitrates usually you need to have the bacteria that feeds on the nitrites develop before you see nitrate spikes. Could you have accidentilly incorrectly tested for nitrates last night?
 
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Electric Warrior

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You are now waiting for your bacteria to develop to take down the nitrites and produce nitrates. For me this part of the fishless cycle always is quicker than the intial part of getting the ammonia down to zero.

I am really not sure how your nitrates went from 80ppm to 5ppm overnight. Provided the water you are using does not have a high level of nitrates usually you need to have the bacteria that feeds on the nitrites develop before you see nitrate spikes. Could you have accidentilly incorrectly tested for nitrates last night?


No, I am pretty sure that I didn't incorrectly test last night, but it is possible that I incorrectly tested or got a false reading when I originally got the 80ppm reading, although I have been pretty careful about all of this. I dosed about 3.5 ppm of ammonia last night because it was at zero, just retested, and ammonia is still there, nitrites still off the chart, and nitrAte is definitely at 5ppm still. Does this seem like it is going somewhere at least?
 

jb1997mcd

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Based on what you have explained things seem to be moving in the right direction. First you get ammonia spikes, once bacteria forms to take this down, you get nitrite spikes (seems like this is where you are at ), and then once bacteria forms to take nitrites down, you get nitrate spikes.

Do you have a lot of surface agitation in your tank? What is the temp? Do you know what your kh his?
 
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Electric Warrior

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Based on what you have explained things seem to be moving in the right direction. First you get ammonia spikes, once bacteria forms to take this down, you get nitrite spikes (seems like this is where you are at ), and then once bacteria forms to take nitrites down, you get nitrate spikes.

Do you have a lot of surface agitation in your tank? What is the temp? Do you know what your kh his?


Uggh!!! I don't this PH swing? There is just surface agitation from the external filter that I have aimed the outlet to the glass, which seems to give more flow across the surface of the water. I just retested, and this where I am at:

Ammonia at about 1ppm now after dosing last night
Nitrite through the roof
Nitrate seems to be at about 80 ppm again!
PH at 6.0???

temp is at 30C.

I am not quite sure why the PH and Nitrate reading keeps fluctuating so much. I am testing correctly.
apitest.jpg
 

jb1997mcd

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The beneficial bateria like oxygen. If you have a spray bar you could have it above the water and have it shoot into the water to creat a lot of surface agitation. This can help speed up the cycle.

Temp is okay I guess, I cycle mine at 80f or 26.5c. I commment on this a little lower.

I think your cycle is still going okay. Again I would wonder why your nitrates are so high when your beneficial bacteria to consume the nitrites don't seem to be present. Did you test the water parameters of the water you used to initially fill the tank and the water I presume you will use for water changes. Sounds like there could be some nitrates in that water.

I am not an expert at all the things that can cause PH to fluctuate. The dropping of your PH is most likely being caused by your higher nitrates. PH can also adjust due to higher and lower levels of oxygen. Water at 30C has a harder time holding oxygen than colder water. If your oxygen is dissipating ( not really what could be doing this in your tank) your CO2 could be rising causing the PH to drop.

Do you know what your KH is? You may want to get a KH/GH test kit. Lower KH's allow for swings in PH. If you have a high KH is has the buffering capability help maintain a steady PH ( ex. your water would have the buffering ability to hand the higher nitrates.) I would suggest getting a KH/GH kit.

There are some water experts out there that could probably share more.

It is funny how you learn so much about water when you decide to keep fish. But what do they say,, take care of your water and your water will take care of your fish.

You will figure it out, you just may learn a little more than you ever thought you would about water chemistry.

jb
 
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Electric Warrior

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The beneficial bateria like oxygen. If you have a spray bar you could have it above the water and have it shoot into the water to creat a lot of surface agitation. This can help speed up the cycle.

Temp is okay I guess, I cycle mine at 80f or 26.5c. I commment on this a little lower.

I think your cycle is still going okay. Again I would wonder why your nitrates are so high when your beneficial bacteria to consume the nitrites don't seem to be present. Did you test the water parameters of the water you used to initially fill the tank and the water I presume you will use for water changes. Sounds like there could be some nitrates in that water.

I am not an expert at all the things that can cause PH to fluctuate. The dropping of your PH is most likely being caused by your higher nitrates. PH can also adjust due to higher and lower levels of oxygen. Water at 30C has a harder time holding oxygen than colder water. If your oxygen is dissipating ( not really what could be doing this in your tank) your CO2 could be rising causing the PH to drop.

Do you know what your KH is? You may want to get a KH/GH test kit. Lower KH's allow for swings in PH. If you have a high KH is has the buffering capability help maintain a steady PH ( ex. your water would have the buffering ability to hand the higher nitrates.) I would suggest getting a KH/GH kit.

There are some water experts out there that could probably share more.

It is funny how you learn so much about water when you decide to keep fish. But what do they say,, take care of your water and your water will take care of your fish.

You will figure it out, you just may learn a little more than you ever thought you would about water chemistry.

jb


Yeah, sorry forgot to mention, I don't know the KH right now.... I am still waiting for the API KH&GH test to some, so until then...
 

4seasons

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Based on what you have explained things seem to be moving in the right direction. First you get ammonia spikes, once bacteria forms to take this down, you get nitrite spikes (seems like this is where you are at ), and then once bacteria forms to take nitrites down, you get nitrate spikes.

Do you have a lot of surface agitation in your tank? What is the temp? Do you know what your kh his?


Uggh!!! I don't this PH swing? There is just surface agitation from the external filter that I have aimed the outlet to the glass, which seems to give more flow across the surface of the water. I just retested, and this where I am at:

Ammonia at about 1ppm now after dosing last night
Nitrite through the roof
Nitrate seems to be at about 80 ppm again!
PH at 6.0???

temp is at 30C.

I am not quite sure why the PH and Nitrate reading keeps fluctuating so much. I am testing correctly.
apitest.jpg
I would recommend a 100% water change with temperature matched dechlorinated water. Then re dose your ammonia but only to 1ppm. 1ppm ammonia should become 2.7ppm nitrite and 1ppm nitrite should become 1.35ppm nitrate or 1ppm ammonia will give 3.65 ppm nitrate. If you show no ammonia or nitrite in 12 hours then up the dose of ammonia to 2ppm and check in another 12 hours. This will tell you where you are at in you cycle.
Right now you are fighting a huge nitrite spike and as nitrite is converted into nitrate you are seeing a rise in nitric acids. Acid is reducing your PH and stalling your cycle. A large water change will reduce the nitric acid, increase PH, get your cycle moving again, ad well as reduce nitrite back to a level you can read.
 
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Electric Warrior

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Based on what you have explained things seem to be moving in the right direction. First you get ammonia spikes, once bacteria forms to take this down, you get nitrite spikes (seems like this is where you are at ), and then once bacteria forms to take nitrites down, you get nitrate spikes.

Do you have a lot of surface agitation in your tank? What is the temp? Do you know what your kh his?


Uggh!!! I don't this PH swing? There is just surface agitation from the external filter that I have aimed the outlet to the glass, which seems to give more flow across the surface of the water. I just retested, and this where I am at:

Ammonia at about 1ppm now after dosing last night
Nitrite through the roof
Nitrate seems to be at about 80 ppm again!
PH at 6.0???

temp is at 30C.

I am not quite sure why the PH and Nitrate reading keeps fluctuating so much. I am testing correctly.
apitest.jpg
I would recommend a 100% water change with temperature matched dechlorinated water. Then re dose your ammonia but only to 1ppm. 1ppm ammonia should become 2.7ppm nitrite and 1ppm nitrite should become 1.35ppm nitrate or 1ppm ammonia will give 3.65 ppm nitrate. If you show no ammonia or nitrite in 12 hours then up the dose of ammonia to 2ppm and check in another 12 hours. This will tell you where you are at in you cycle.
Right now you are fighting a huge nitrite spike and as nitrite is converted into nitrate you are seeing a rise in nitric acids. Acid is reducing your PH and stalling your cycle. A large water change will reduce the nitric acid, increase PH, get your cycle moving again, ad well as reduce nitrite back to a level you can read.


This might sound kind of stupid, but what is the best way to temp match 200L of water?
 

4seasons

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Take a cup and fill it with water from you tank. Set it next to the bucket you are using to refill your water. Stick your finger in the cup and then the bucket. Adjust the hot/ cold mix till it feels the same. If you use a hose directly into the tank do the same thing but into an empty bucket first to match. You can also use an extra thermometer to get it exact but a couple of degrees cooler won't hurt anything.
 

drobbyb

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That pH reading doesn't surprise me. It looks like your kH is on the low side (which is good if you plan on keeping acidic loving fish.) But it might make finishing out your cycle a little problematic. With those readings, you might stall out at this point. I would do a complete water change and re-dose to 2.0 ppm ammonia. Your a-bacs will turn this into 5.0 ppm nitrite in 24 to 48 hours depending on when they rebound from the pH crash and then your cycle will continue. You can buffer your pH with baking soda, but don't add a lot of it, a tablespoon would be good in 200L. This would give you a slight rise in pH and a good bit of buffer to hold you there.
 

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