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Having serious issues with my first fishless cycle.

2K views 18 replies 10 participants last post by  Reginald2 
#1 ·
Hey everyone, im going to try and keep this short,

I started cycling my 75 gallon 6 weeks ago, everything was going great, after 1.5 weeks my ammonia was already converting to Nitrites, and I was having to re dose my ammonia up to 3ppm every day.

But now my tank wont convert the ammonia to nitrite, I have dosed ammonia ONCE in 2 weeks...

What could be going on here? I have my heat high, I have a large air stone creating a ton of aeration

The only thing I have read that I think could be the problem is my PH has dropped very low, I just tested with the API test and my PH doesnt doesnt get a reading on the LOW PH scale, its below 6. My PH out of the tap is about 7.5 and stays stable after 24 hours.

If the PH is the problem what are my options to raise it? Should I do a water change?

I was really hoping to be finished the cycle by now, and after my first 2 weeks I really thought I was going to have a nice smooth cycle, but its really stalled.

Any advice is very much appreciated
 
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#2 ·
I am not an expert by any means, but here is my understanding. The bacteria use carbon to do their thing and will actually lower the KH of the water when breaking down large amounts of waste. Lower KH = lower PH. And I also understand that extremely low PH can inhibit the beneficial bacteria. So, knowing all of this, I think yes, do a water change and get the PH back up. After that make sure to do water changes accordingly to so that it does not drop below 7.

Hopefully the bacteria you had before isnt gone and your cycle will start back up, but it may take another week or two to see progress again.

After you start seeing your ammonia being converted, be aware that it is not uncommon for the second part of the cycle (nitrite -> nitrate) to take a bit longer than the first.
 
#5 ·
Two weeks for ammonia to drop to zero sounds about right at which point there should be nitrites which are then converted to nitrAtes.
Too much ammonia can actually stall the process in nitrite stage and some reduce the amount of ammonia by 1/2 once nitrites appear for this reason(seem's to work for many) So however many drops you used to get 3ppm,you could decrease the drops by 1/2.
Other possible sources of ammonia are from organic break down in/on the substrate,some trapped in filter,fish foods,and or plant matter as it dies off.
Plants can help take up ammonia but there may be just too much ammonia and too few plants.
Could try reducing the ammonia as mentioned,reduce light intensity,and increase CO2 along with plant mass and see if thigs don't improve over a few week's.
At a pH of 6 I would not worry bout ammonia which is much less harmful ammonium at pH mentioned ,but would simply add more plants and stock the tank gradually while doing way with the ammonia dosing altogether.
Healthy plant's are best biological filter and are a good tool for managing a glass box of water that we begin polluting the moment we add fish.
 
#7 ·
It's been a while since I tried a fishless cycle, but I seem to remember it taking closer to two months than two weeks maybe longer to be honest.

If I were in your situation, I would probably change most of the water to sort of reset all the levels, then try dosing a small amount of ammonia (like just enough to show up on the test) and testing again in a few days to see if it's progressing.

Like AHGoodwin said I feel like once the nitrites started showing, it ended up being quite a bit later before the nitrates started showing up.

The good part is, you're getting a large dose of what fishkeeping/plantkeeping is. It takes longer than you think it should, nothing goes right, and the only cure for a lot of things is more patience. :)

Hang in there. My first fishless cycle was one of the neater things I've done with aquariums and it'll be nice to see it come to fruition.

Is there anything alive in the tank (like plants or anything)?
 
#10 ·
I think some of you guys are misunderstanding the situation haha

My cycle was going fine for the first 3 or 4 weeks, my tank was converting ammonia fine, and my nitrites were super high, then all of a sudden for the past 2 weeks or so my tank wont convert the ammomia, its stalled hard.

So doing a large WC is the way to go, then carry on and see if that helps?
 
#11 ·
I have a QC question for you. When you use the api test kit, are you using the cap instead of your finger. And are you shaking the tube so your arm hurts a little and giving it full time for the color to develop? These test kits can be very finicky.
 
#12 ·
I use the cap, and then I give it about 3 shakes and then I wait as directed on the instructions..

Ive been fish keeping for a year and a half, have had 2 tanks, im not a total noob... but I decided fish in cycle was not humane and wanted to go with a fishless cycle this time, so this is new to me.

Testing my water is not.

I just did a 50% WC and im now going to wait an hour, test my ammonia, my PH, and then I will re dose my ammonia back up to 3PPM
 
#16 ·
I use the cap, and then I give it about 3 shakes
The test requires 5 seconds. Look at a second hand and shake your hand three times. I bet you still have three seconds left which means you only shaking it for half of the required time. Believe it or not, when it comes to chemical reactions, tests are very finicky so I am just trying to help to cover all of your basis.

I also agree with the above that your nitrosomonas could have perished or gone dormant when you stopped dosing ammonia. Remember ammonia is being dosed every day by fish and nitrosomonas needs that to take you to the nitrate cycle. Without a constant supply of ammonia your bacteria can't thrive. Even though your test will eventually read zero that doesn't mean ammonia isn't present, it means it is being consumed as soon as it is produced.

I would almost bet that if its not the first one its the other.
 
#15 · (Edited)
1 teaspoon per 30 gallons raises the KH by 2 degrees. When I cycle a tank I try to keep my kh at 4. Which is pretty easy once you figure out exactly what you need, take detailed notes. Once you add baking soda you will see an immediate change in your kh and ph, just try to keep it from falling to low to avoid a cycle stall.
 
#17 ·
Bacteria can survive for weeks without a source of ammonia, I've proven this.. it's very simple, your cycle stalled because your ph crashed, a simple wc is all that is needed.. no need for calcium carbonate unless your tap water is lacking to begin with. Sounds like it's just fine as you've had a successful start. .
 
#18 ·
ok, so its been 5 days now since i did the 50-60% WC and i added Baking Soda.

my tank is doing great now, i actually think my cycle finished in this time?

so my tank seems to be fully converting Ammonia to Nitrate in 24 hours. i have been dosing 3ppm ammonia every day, and every 24 hours ill test again and the ammonia and Nitrite are at 0

i just tested my Nitrate for the first time since the WC and its super high.

what do you guys think? did my tank pick up where it left off, and actually completed the cycle? keep in mind my tank has been cycling since June 22nd.

what should i do before i know for 100% fact my tank is fully cycled? sorry for the noobie questions, like i said, first time fishless cycling...

im going to be buying 600 dollars worth of Discus (6- 4" Discus) so obviously i want to be 100% sure before i spend all that money..
 
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