New Tank Cycle. General Questions/Help

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DonnellH1525

Aquarium Advice Newbie
Joined
Apr 18, 2022
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I recently setup a new fish tank. It’s a Fluval Flex 32.5g Freshwater. It has been running for 2.5 weeks now. I am doing a fish-less cycle. Only thing in the tank is substrate, rocks for decoration, a airstone and about a dozen live plants that are thriving. Temperature is 78°, PH is 7.4 and my tanks light system starts at 6am and shuts off at 8pm.

3 days after conditioning water and letting everything settle I added Fritz Zyme Fishless Fuel to bring the ammonia to 4.0+ ppm. I tested my aquarium water with my API Master Test Kit before adding Fritz Zyme Fishless Fuel and Fritz Zyme 7 Live Nitrifying Bacteria to tank. The ammonia, nitrite and nitrate were all 0 ppm. After adding Fishless fuel and 7 I checked the water again 1 hour later. Ammonia was at over 4.0 ppm++ while nitrite and nitrate was at 0. By day 2 my ammonia was slowly lowering and my nitrite shot up to 2.0 ppm while my nitrate started to rise as well. Fast forward 2 weeks to today, I have not touched the tank in any way and my ammonia has dropped down to 0 three days ago and my nitrite was down to .25 ppm by yesterday. My nitrates are over 20 ppm now. I tested today and noticed that my nitrite has gone back up to .5 ppm+. I am also starting to see a little algae growth on my rocks and air stone tubing. I’m scratching my head because I thought I was almost complete with my cycle but I guess not. I have read various information and talked to local pet stores all with varying opinions.

Now to my questions and concerns:

My first question is am I doing this right? I have read that you are supposed to continually add ammonia when it drops below 1.0 ppm to the tank until you see ammonia and nitrite spike then drop back to 0ppm within a 8 hour period. I have also read that once you add the ammonia/beneficial bacteria to the tank to just wait until the spikes occur and drop to 0 without adding anything or regardless of time that it takes. When this is complete do a water change and add fish (I have been doing this method but still no water change or fish).

Second question. If my ammonia is officially at 0 ppm for a few days, why would my nitrite lower to .25ppm then jump back up between .5-1.0ppm? Should I be adding more?

Third question. If some of the algae in my tank is brown, I have ready that it could be because of high nitrate. My current nitrate levels have been over 20ppm for 3 days now. Should I even concern myself with this by doing a water change at this time?

Last question. I know this can take a few weeks to complete so with this information I’ve shared should I tweak anything or keep doing what I’m doing? Am I pretty much buggin over making this go perfectly so i don’t kill my fish when added. I would appreciate the help and tips from the pros. Thank you!
 
Test daily. If your ammonia drops below 1ppm, top it up to 2ppm. When you can top up ammonia to 2ppm and 24 hours later see zero ammonia and nitrite you are cycled.

Spiking ammonia just once and waiting for it to go to zero wouldnt be enough to say you are cycled. Your tank wont be able to process out all the waste a tank full of fish in a timely manner. You could do this and add a small amount of fish and manage water quality through water changes on much the same way as a fish in cycle, but with the benefit of some established bacteria though.

Why your tests dont seem to produce inconsistent results? These are home test kits, not laboratory testing. All sorts of things can throw off test results, even down to the quality of light you read the test in. Nitrite can cause false positive test results for nitrate for instance. Perhaps the 0 ammonia was wrong, perhaps the higher reading is. Perhaps plant melt is adding ammonia. Many reasons why a test produces inconsistent results.

The brown algae is common in newly established aquariums. Its actually called diatoms and it is feeding on imbalances in nutrients in the water. It could be high nitrate that they are feeding on, but in a new tank its more likely silicates from the substrate, glass, sealant. When these nutrients get used up the brown algae will die off, usually in a couple of months.

Unless your test readings get beyond readable levels, there is little point in doing a water change. You might want to do one if for instance nitrite goes off the chart and you can no longer monitor increases or decreases in this parameters. A water change can also kick start a stalled cycle by replenishing carbonate hardness.
 
I haven't used Fritz. And not sure how it would effect the cycle process. Check out these articles in case you haven't seen them yet.

Usually I have done fish in cycling. But the last time I did a fishless was for a SW tank. Slightly different but similar. I thought it would take forever, lol!

https://www.aquariumadvice.com/the-almost-complete-guide-and-faq-to-fishless-cycling/

https://www.aquariumadvice.com/tips-and-tricks-for-your-fastest-fishless-cycle/
@Autumnsky thank you for the links. I appreciate all the credible sources just so I can learn about this and do better!
 
Test daily. If your ammonia drops below 1ppm, top it up to 2ppm. When you can top up ammonia to 2ppm and 24 hours later see zero ammonia and nitrite you are cycled.

Spiking ammonia just once and waiting for it to go to zero wouldnt be enough to say you are cycled. Your tank wont be able to process out all the waste a tank full of fish in a timely manner. You could do this and add a small amount of fish and manage water quality through water changes on much the same way as a fish in cycle, but with the benefit of some established bacteria though.

Why your tests dont seem to produce inconsistent results? These are home test kits, not laboratory testing. All sorts of things can throw off test results, even down to the quality of light you read the test in. Nitrite can cause false positive test results for nitrate for instance. Perhaps the 0 ammonia was wrong, perhaps the higher reading is. Perhaps plant melt is adding ammonia. Many reasons why a test produces inconsistent results.

The brown algae is common in newly established aquariums. Its actually called diatoms and it is feeding on imbalances in nutrients in the water. It could be high nitrate that they are feeding on, but in a new tank its more likely silicates from the substrate, glass, sealant. When these nutrients get used up the brown algae will die off, usually in a couple of months.

Unless your test readings get beyond readable levels, there is little point in doing a water change. You might want to do one if for instance nitrite goes off the chart and you can no longer monitor increases or decreases in this parameters. A water change can also kick start a stalled cycle by replenishing carbonate hardness.
@aiken drum thank you for the input. I have already started dosing with Fishless fuel again to bring the ammonia back up. One question is I have seen both 24 hours for it to drop to zero and 8 hours to drop to zero. Is the latter overkill?

For the brown algae, I have seen a little green algae as well growing on a rock. Read something that this is potentially a good thing? Not sure but does not seem like I huge deal to the fish within reason whenever I get to that point.

All my levels are still readable on the chart. I appreciate the input on these test being a good base but not perfect and if it is reading off the chart without coming down to do a water change. For now I will just let it run it’s course and eventually (hopefully soon lol) add some fish.
 
Ive never heard of anyone having issues stocking tanks once they have got to a stage of cycling out 2ppm ammonia in 24 hours. Ive stocked tanks once i can cycle out 1ppm ammonia in 24 hours. I guess it depends on how heavily stock your tank to start with. Even after cycling i still tend to start moderately and build things up over time.

Green algae is something you cant really avoid. If you have light you will grow some green algae. Green algae will outcompete brown algae for nutrients, its just what happens in an aquarium. Its a matter of controlling things so you are happy with the balance. For instance if you have plants that need light, you need to balance the plants need for light with the amount of algae in your tank and how much you are prepared to manually clean up. I know people with no plants in their tanks who really cut back on light intensity to keep algae growth at a minimum. A bit of algae growth is healthy and wont harm your fish, just might be a bit unsightly depending on your personal preference on what you want to see. I think a bit of algae growth on the aquascape looks more natural, and i try to keep plants and the glass front algae free.
 
Ive never heard of anyone having issues stocking tanks once they have got to a stage of cycling out 2ppm ammonia in 24 hours. Ive stocked tanks once i can cycle out 1ppm ammonia in 24 hours. I guess it depends on how heavily stock your tank to start with. Even after cycling i still tend to start moderately and build things up over time.

Green algae is something you cant really avoid. If you have light you will grow some green algae. Green algae will outcompete brown algae for nutrients, its just what happens in an aquarium. Its a matter of controlling things so you are happy with the balance. For instance if you have plants that need light, you need to balance the plants need for light with the amount of algae in your tank and how much you are prepared to manually clean up. I know people with no plants in their tanks who really cut back on light intensity to keep algae growth at a minimum. A bit of algae growth is healthy and wont harm your fish, just might be a bit unsightly depending on your personal preference on what you want to see. I think a bit of algae growth on the aquascape looks more natural, and i try to keep plants and the glass front algae free.
@aiken drum okay so more questions.

1) I have been re dosing ammonia to 2.0ppm+ and it drops to zero well within the 24 hour period. Nitrites does not seem to want to drop at all. Nitrites are sitting at 2-5ppm for days now.

2) my nitrAtes have dropped significantly all by themselves. I still have not done a water change nor added fish. I know these tests are not as accurate as a lab but I though nitrAtes only dropped if you did a water change. Unsure how I would be getting this reading. It’s gone from 40-80ppm down to 5ppm. How? Is this is a good thing?

3) brown algae is still growing and green algae has been also growing. I am now noticing blue algae as well which I read could be because of too much ammonia.

4) should I do a 25% water change just to bring levels down so I can read nitrites or just continue to let it do it’s thing by adding Ammonia when it drops under 1ppm?
 
1. What you are seeing is normal. Completing the nitrite to nitrate stage tends to take longer than the ammonia to nitrite stage. Last time i cycled a tank, i was seeing zero ammonia after 2 to 3 weeks, zero nitrite took another 5 or 6 weeks.

2. Yes, under normal circumstances nitrate will only be removed by water changes. I would put this down to testing inaccuracy. Nitrate is very difficult to test for accurately, even for professionals in a lab. 2 things that can contribute to false nitrate readings are nitrite and water conditioners.

3. Apart from saying same causes as green algae, cant help you with blue algae, not something ive has experience of. Control your lights, manually clean things up. Diatoms will take a few months to start dying off.

4. I would do water changes to keep things within readable levels. Just my preference, not really essential. Do your water test, clean up any algae, change some water to bring parameters to readable and hoover up any removed algae while you are at it, redose your ammonia.
 
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Check temperature and oh in the earlier linked article, tips and tricks for your fastest fishless cycle, about 2/3rds down in
ammonia...nitrite...nitrate
it discusses some effects of zeroing in on pH for feeding bb.
 
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