Cycling Problem

[Ricksza]

HELP !
I wanted to set up a 10-gal quarantine tank. So I pulled an extra double sponge filter from another tank (been in there for months) and put it in the new tank with 2-day-old treated water. I added ammonia to get 2.0ppm. At this point, I decided to add additional sponge filters to seed for other tanks that I'm setting up in the near future. The next day, I check the Ammonia - it's down to 0.5ppm and Nitrite is 2.0ppm, so I add Ammonia up to 1.0ppm. 16 hours later Ammonia's down to 0.5ppm so I add Ammonia up to 1.0ppm. Nitrite is still 2.0ppm. Next day, Ammonia is 0ppm, Nitrite is 2.0ppm and Nitrate is 40ppm. I bring Ammonia up to 4ppm and 8 hours later it's down to 0.25ppm, so I figure all's good with the world. I continue like this for the next three days, Ammonia drops and I add more. Suddenly on the 4th day, Ammonia isn't dropping, Nitrite is 0ppm, Nitrate is still 40ppm, so I do a 50% water change and add some API Quick Start the next day. The following day, Ammonia is dropping again, so I add to go back up to 2.0ppm. This goes on for a couple of days. Now Ammonia is 1.0ppm and not dropping, Nitrite is still 0ppm, Nitrate is 40ppm. I just checked pH and that's at no higher than 6.0, my tap water is 7.6. There is nothing in my tank other than water and filters. What can cause the pH to drop? I understand that low pH can stop the cycle. Will it stall the cycle or totally kill it? Is there any way to recover?

 

[Sorg67]

I think you may have overdosed with ammonia and gotten things a bit out of whack.

If you do a few big water changes, you may be able to get things back on track. However, I would wait until others comment. I am just learning about the cycle process.

I wonder if a sudden increase in ph resulting from higher ph tap water would have an adverse impact on the BB. Maybe do successive small water changes to slowly bring ph back to tap water ph. Once your tank water is back to ph of tap water, then do more modest ammonia dosing and see if you can stabilize.

I am developing the opinion that modest dosing and consistent water parameters will help achieve a strong stable cycle.

The following members are more knowledgeable than I am. Hopefully they will chime in. I have learned most of what I know from them.

John58ford
mattgirl
Momgoose56

 

[mattgirl]

HELP !
I wanted to set up a 10-gal quarantine tank. So I pulled an extra double sponge filter from another tank (been in there for months) and put it in the new tank with 2-day-old treated water. I added ammonia to get 2.0ppm. At this point, I decided to add additional sponge filters to seed for other tanks that I'm setting up in the near future. The next day, I check the Ammonia - it's down to 0.5ppm and Nitrite is 2.0ppm, so I add Ammonia up to 1.0ppm. 16 hours later Ammonia's down to 0.5ppm so I add Ammonia up to 1.0ppm. Nitrite is still 2.0ppm. Next day, Ammonia is 0ppm, Nitrite is 2.0ppm and Nitrate is 40ppm. I bring Ammonia up to 4ppm and 8 hours later it's down to 0.25ppm, so I figure all's good with the world. I continue like this for the next three days, Ammonia drops and I add more. Suddenly on the 4th day, Ammonia isn't dropping, Nitrite is 0ppm, Nitrate is still 40ppm, so I do a 50% water change and add some API Quick Start the next day. The following day, Ammonia is dropping again, so I add to go back up to 2.0ppm. This goes on for a couple of days. Now Ammonia is 1.0ppm and not dropping, Nitrite is still 0ppm, Nitrate is 40ppm. I just checked pH and that's at no higher than 6.0, my tap water is 7.6. There is nothing in my tank other than water and filters. What can cause the pH to drop? I understand that low pH can stop the cycle. Will it stall the cycle or totally kill it? Is there any way to recover?

OK, you pulled a dual sponge filter from a cycled tank. Normally when doing this you aren't going to get the nitrite spike. I have to think the bio-load in the tank you pulled the sponge from had a much lower bio-load than the original 2ppm ammonia you added. That amount threw the bacteria into overdrive trying to catch up with the higher bio-load. This is known as a mini-cycle.

I don't totally understand the science behind it but yes, for some folks the cycling process will cause the PH to get lower. Something about all the buffering agents in the water get depleted. I have to think your cycle is stalled so do a water change(s) to get the PH back up to the level of your source water and this cycle should start moving forward again.

I would only be adding 1ppm ammonia each time it goes back to zero until this cycle stabilizes. Once it does you can gradually increase the amount of ammonia to grow a bigger colony of bacteria .

I do have to ask why you are aging your water change water though. Any of the many water conditioners will make most of our water safe to use immediately and you will be using fresh water instead of 2 day old stale water..

 

[Ricksza]

OK, you pulled a dual sponge filter from a cycled tank. Normally when doing this you aren't going to get the nitrite spike. I have to think the bio-load in the tank you pulled the sponge from had a much lower bio-load than the original 2ppm ammonia you added. That amount threw the bacteria into overdrive trying to catch up with the higher bio-load. This is known as a mini-cycle.

I don't totally understand the science behind it but yes, for some folks the cycling process will cause the PH to get lower. Something about all the buffering agents in the water get depleted. I have to think your cycle is stalled so do a water change(s) to get the PH back up to the level of your source water and this cycle should start moving forward again.

I would only be adding 1ppm ammonia each time it goes back to zero until this cycle stabilizes. Once it does you can gradually increase the amount of ammonia to grow a bigger colony of bacteria .

I do have to ask why you are aging your water change water though. Any of the many water conditioners will make most of our water safe to use immediately and you will be using fresh water instead of 2 day old stale water..

The only reason I waited to put the seeded filter in was because I wanted to get the other filters set up in there first (I'm adapting power heads to sponge filters) and allow the water temperature to get settled. The seeded filter was from a low bioload, shrimp tank. I thought the cycle was working because I had the 2 to 0 Ammonia drop for a couple of days. I did a 50% water change today, that brought the pH up and the Ammonia & Nitrate down. Added Ammonia to 1ppm. Hope the cycle continues.

 

[John58ford]

Things I have learned about this specifically:
1: you need to keep your water parameters level in pH. If your pH is dropping your bacteria is de mineralizing the water and you have used up your Waters natural buffering capability.

2: as pH drops, so does the effect of ammonia on living things, it can stall a cycle just as too high of a pH from over buffering (adding Coral and such)can kill one. If the water can support having high concentration of ammonia due to low pH, the bacteria doesn't have a job to do.

3. A higher tank temperature encourages bacterial reproduction, I have used temperatures up to the mid 80s to get it done faster.

4. Water change until you are down to 20 ppm nitrate and it will likely solve your pH buffering.

5. Wow you have built quite the fertilizer factory, I'm fairly impressed.

6. There are actually filter materials that can grow bacteria that will eat nitrates and turn them into nitrogen gas, the cycle for them to do that takes a longer time and they need a slow flow rate but it may be with looking into.

Good luck with it!

Edited to add a thought:
4ppm daily to 2ppm will cause some of your already established stuff to die off. I would get it running smooth for about 3 days to stabilize, then put a polisher in it, maybe a HOB with nothing but polyfill batting (cheapo filter floss) and give all the sponges a good squeeze and a shake. Just let the polisher eat the dirty stuff and toss it. Remove the polisher and run a few more days while dosing your appropriate amount of ammonia and you'll probably be good to go.

 

[Ricksza]

Things I have learned about this specifically:
1: you need to keep your water parameters level in pH. If your pH is dropping your bacteria is de mineralizing the water and you have used up your Waters natural buffering capability.

2: as pH drops, so does the effect of ammonia on living things, it can stall a cycle just as too high of a pH from over buffering (adding Coral and such)can kill one. If the water can support having high concentration of ammonia due to low pH, the bacteria doesn't have a job to do.

3. A higher tank temperature encourages bacterial reproduction, I have used temperatures up to the mid 80s to get it done faster.

4. Water change until you are down to 20 ppm nitrate and it will likely solve your pH buffering.

5. Wow you have built quite the fertilizer factory, I'm fairly impressed.

6. There are actually filter materials that can grow bacteria that will eat nitrates and turn them into nitrogen gas, the cycle for them to do that takes a longer time and they need a slow flow rate but it may be with looking into.

Good luck with it!

Edited to add a thought:
4ppm daily to 2ppm will cause some of your already established stuff to die off. I would get it running smooth for about 3 days to stabilize, then put a polisher in it, maybe a HOB with nothing but polyfill batting (cheapo filter floss) and give all the sponges a good squeeze and a shake. Just let the polisher eat the dirty stuff and toss it. Remove the polisher and run a few more days while dosing your appropriate amount of ammonia and you'll probably be good to go.

After the water change, the pH has remained steady at 7.6, Nitrite is 0ppm

Every morning I check my water parameters. The Ammonia is 0.25ppm, so I add more to bring it to 2ppm.

My water temperature is staying at 88° due to the power head motors. For now, I believe it's okay for bacteria growth, but before any creatures go in, I'll need to switch back to air pumps for lower temperatures.

The tank I'm cycling is on the lowest shelf of my rack, so I used a pump for water changes. Well yesterday it gave up the ghost, so it's on to using the Python until I find a better pump. More water changes should bring the Nitrates down.

I don't expect the sponge filters to be too dirty, since there is nothing in the tank except water and sponge filters.