Aquarium Advice - Aquarium Forum Community

Aquarium Advice - Aquarium Forum Community (
-   Freshwater & Brackish - General Discussion (
-   -   Aquarium not cycled after 2 months (

AKLB 08-20-2018 02:57 PM

Aquarium not cycled after 2 months

I've been fishlessly cycling my planted 200l/55g aquarium since the start of June using ammonia. Within the first few weeks my ammonia levels were starting to drop off and I was beginning to see nitrites and nitrates, and apart from a brief period when my nitrites stopped reducing, everything seemed okay.

Around a week ago it seemed like my cycle was nearly finished as 4ppm of ammonia was being reduced to 0.25ppm and all nitrites were disappearing within 24 hours. However, since then my ammonia has suddenly stopped converting into nitrites and does not reduce at all from 4ppm for several days. As I am writing this post my ammonia is at 4ppm, 4 days after redosing.

What can I do to finish this cycle? I've looked online, and some people are saying I could use Tetra Safestart and stock a small group of fish to finish the cycle. What do you think about this?

Over 2 months seems like a very long time for my aquarium to not be anywhere near finishing.

Hope you can help,

ZxC 08-20-2018 02:59 PM

pH of the tank water?

AKLB 08-20-2018 04:18 PM

Between 8 and 8.2

Delapool 08-20-2018 07:34 PM

When was last water change? Might have used up some elements although ph looks good.

AKLB 08-21-2018 06:15 AM

A couple weeks ago, I was under the impression you werenít supposed to do water changes unless nitrites spike. Iím guessing thatís wrong?

Delapool 08-21-2018 06:56 AM

Imo water changes would be fine and quite often done to lower readings down from Ďoff-the-chartí to within test kit range. Also useful where ph drops too low (and useful elements have been deleted that bacteria need). As well there may be other elements used, so sometimes a water change kick-starts a stalled cycle.

Copied in text:

1 ppm ammonia --> 2.7 ppm nitrite --> 3.6 ppm nitrate.

For every gram of ammonia oxidised into nitrate 4.8 grams of oxygen is used, 7.14 grams of calcium carbonate is used (thus why pH crash can occur in tanks with to little buffering capacity).

AKLB 10-06-2018 07:24 AM

Well itís been a little over a month since I made this post, and my tank still doesnít even seem to be nearly cycled. Ammonia is still taking ages to come down.

Any more help?

Delapool 10-06-2018 08:20 AM

So ammonia was coming down but now isnít? What are all your chem readings? And water changes made no difference?

Beginning to sound like a stalled cycle. I assume tap water hasnít changed and the water conditioner you are using is just getting dosed as per bottle? Over-dosing can sometimes slow down cycling.

AKLB 10-06-2018 02:22 PM

Ammonia is around 4ppm (redosed it to around 4ppm 3 days ago after a water change). Nitrite is around 0ppm. Nitrate is very high, somewhere between 80ppm and 160ppm. pH is around 8.4.

The last time I performed a water change was 3 days ago, and I have been doing it every week or so since this post was created.

My tap water hasnít changed. I may have been slightly overdosing the water conditioner after a water change as the recommended dosage is so small, but this shouldnít have been overdosed by a crazy amount.

Not sure if this helps at all, but the aquarium is planted with java fern, anubias, cryptocorynes, dwarf floating lettuce and some marimo moss balls, which I fertilise with Seachem Flourish Excel according to its instructions. Maybe planting some more could help? I tried adding some vallisneria a while ago but they all died fairly quickly.

The water conditioner is Seachem Prime. I also have an airstone bubbling away as I read that it could help speed up the cycle.

Just out of interest, what do you think about products aimed at speeding up a cycle, such as Tetra Safestart?

Sorry for the long reply, Iím just trying to list everything I can about the tank in case something I havenít thought of could be stopping my cycle.

Delapool 10-06-2018 08:56 PM

Aquarium not cycled after 2 months
You could try the bacteria in a bottle. Products can be hit or miss but rarely cause issues. Go with a leading brand from a shop that stored it well (ie not in some shed out back over summer). Iíve used and thought helpful.

I wouldnít stock fish yet until have an idea of cause.

Is ammonia reducing but just very slowly?

I assuming tap water is 0 for ammonia and nitrates. And after you do a water change, that nitrates drop and then rise again. If the case, it sounds more a mini-cycle where nitrates are being produced but the ammonia to nitrite converting bugs have taken a hit to the population and are re-building. Just a thought to check. Nitrite at 0 says that is fine.

In a young tank this could be from any meds, liquid carbon, algal, etc treatments or from too much cleaning of filter. It could also be from really gunked up filter (bugs get covered) or filter too small but this tends to be from goldfish kept in very small tanks (filter canít handle bioload - doesnít sound a problem here).

Thatís all I can think of. Might get some other thoughts from others. The water conditioner and plants all sound fine. Ph sounds fine.

One very last thought is I assume the test kit is working fine. Generally these hobby test kits are fine for what we do but can give major errors if eg bottle cap left off. It doesnít sound the case but posting all I can think of / heard of. Iíve found the test kits pretty good myself.

All times are GMT -4. The time now is 12:01 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.