Newbie Needs Help - Tank Cycle Stuck?

[TheTrueGeek]

Hi All

Hope someone can give me some advice/pointers - would really appreciate it. Before posting on here, I've tried to do my research, but still need guidance.

I bought a new 46L "tank kit" about 4 weeks ago. After setting up the tank and getting the substrate/decor and water in, and adding the Nutrafin Aqua+ and Cycle - I let the tank 'mature'.

WEEK ONE: Water was nice and clear for the first day or so. Then turned milky white which was a good thing (I read). It then cleared rapidly. At that stage I was unaware of fishless cycling (sorry!), and was advised to buy some fish (by multiple stores I visited) to get things going in the tank.

WEEK TWO: I introduced 4 Zebra Danio. One died within 36hrs so now have 3. They seemed happy enough. Bought an API testing kit to monitor water conditions. PH 7.5 (steady) Ammonia 0.25ppm Nitrite 0 Nitrate 0.

WEEK THREE: Fish still swimming about happily. I know the Zebra Danio need more to school, but reluctant to add more fish to the tank just yet. PH 7.5 (steady) Ammonia 0.25ppm Nitrite 0 Nitrate 0.

WEEK FOUR: Fish are still happy. I really want to add more to the community as I feel the fish are beginning to pick on one another a little more. PH 7.5 (steady) Ammonia 0.25ppm Nitrite 0 Nitrate 0.

As you can see, the water chemical levels have not changed at all. I've no idea where in the tank cycle I am as I have not had any spikes and no "registerable" levels of Nitrite or Nitrate.

Does anyone have any advice or guidance in general to give me? Is it safe/advisable to add more fish?

If you need any more information from me, please let me know and I'll happily oblige.

Thanks,
TTG

 

[fluttermoth]

to the forum.

It's early days for a fish in cycle. Are you testing the water daily? You need to be doing enough water changes so that neither your ammonia or nitrite never gets to more than 0.25ppm. While zebra danios are hardy and won't be killed by that level of ammonia, it will still be doing irreperable damage to their gills, reducing their ability to absorb oxygen from the water.

I would have expected to see some change in those levels by now; are you using a dechlorinator at every water change? Are you doing anything to the filter, apart from wash it out in old tank water?

Don't add any more fish until you have had a week's worth of zero readings for both ammonia and nitrite for a week, without needing to do a water change.

Zebra danios or really not suitable for smaller tanks like yours. While they're only small themselves, they are very fast swimmers, and need a tank that is three feet long, at the very least. I'd strongly advise you to consider taking them back and doing a fishless cycle, to be honest, but at least exchanging them for something more suitable for your tank size, in the long term.

 

[TheTrueGeek]

Hi Fluttermoth - thanks for taking the time to reply.

I am testing the water pretty much every other day as there have been no variations in the results at all. If I started to see some sort of change, I'd test more regularly to keep a closer eye on what's happening. But this is where my confusion lies... there are no changes in my water conditions at all - just the numbers I mentioned previously?! At the very least I would expect to see Ammonia rise because of the fish - or Nitrate as an end product... something?!

So far no water changes have been done as I am worried that I will disturb the tank cycle. I thought I was meant to keep the water the same and only change it if levels of Ammonia rise too high, or if the tank has cycled and there is Nitrate in the water. The water is nice and clear and the fish do not seem distressed and are swimming about. Do you recommend regular water changes regardless in my situation? (ie. chemical readings). The filter has not been interferred with at all, so am confident that is working as it should.

You also advised not to add more fish until I've had a weeks worth of zero readings, I've had almost 3-4 weeks of that - so will adding more fish kick start the cycle?

Interesting to hear that the Zebra Danio's are not best suited for my tank. I like these fish, I think they have a great personality but if they are not suited to the size I have, I will need to re-think which fish to have... especially at the start of this tanks life. Do you have experience of other hardy fish which are better suited?

Sorry to answer your questions with more questions!

 

[Xraymark]

Test your tap water for ammonia.

 

[TheTrueGeek]

Thanks Xraymark - will do so when I get home from work, but not sure that will explain what's happening in the tank cycle I'm experiencing?

 

[fluttermoth]

Oh, don't worry about asking lots of questions; that's what we're here for

You won't disturb the cycle by changing water. Your filter will still cycle with a level of ammonia that's too small to show up on our tests.

Your ammonia level is too high; a level of 0.25ppm is harmful to fish, any level over zero is, I'm afraid. The water being clear is a bit of a misleading thing; sulphuric acid is clear, but you wouldn't want to be putting fish in it, would you?!!

I don't know why your cycle doesn't seem to have started; do you know the hardness of your water? Very soft water can inhibit the growth of the bacteria.

If I were you, I'd do a big water change; leaving just enough water in the tank for the fish to swim upright and refill with temperature matched, dechlorinated water. If you haven't changed the water at all for four weeks, it could be lacking some of the trace minerals needed for the bacteria to grow; that's one of the main reasons for doing weekly water changes, even if your nitrate isn't high; to replenish those things we can't/don't test for. A big change might be all that's needed to kick start it.

Or you could try and get hold of some mature media to seed your filter; some fish shops will give you some if you ask nicely

You definitely don't want to be adding any more fish yet; that could cause the ammonia to rise to an even more dangerous level; you need zero readings for both ammonia and nitrite for a week before your can be confident your filter is cycled.

As for recommending other fish species, I wouldn't want to do that until I knew the hardness of your water and the dimensions of the tank; those are important factors that need to be considered for stocking

 

[TheTrueGeek]

Again, thank you for taking the time to give me a detailed and informative response. When I get home this evening I will make sure I perform a large water change. Of course dechlorinating the water first, but should I also add more Nutrafin Cycle into the tank once the water has changed?

Not too sure what level of hardness my water has, but I know for sure it is hard water.

As for my tank details, it's the 46 Litre Fluval Edge - measures 43cm wide, 59.4cm high and 26cm from front to back. Linked Fluval Edge Aquarium 46L in case anyone is interested.

 

[OldMan47]

A nice tank you have there True Greek.
Hard water means that you do not need to worry too much about a drop in pH. You will be able to step though a fish-in cycle with no real problems. As fluttermoth said, water changes will do no harm at all to the cycle of your filter. If you have used a liquid type test for ammonia and nitrites and have seen none, chances are good that you have adequate bacteria in your filter to take care of your present fish stock levels. I make the assumption that is true. That would mean that you can begin to slowly increase you fish stock level. If the assumption is not correct, you will need to adjust your actions accordingly.

 

[TheTrueGeek]

Thank you OldMan47! - feeling more positive having read that and Fluttermoths responses. My test kit is a liquid test kit by API as I heard they are far more reliable. Your assumption is very nearly true - I'm reading zero for Nitrites and Nitrates, but 0.25ppm for Ammonia. This has been the case for a long while now with no change or variation. As per Fluttermoths comments yesterday, I did a big water change yesterday evening. So far so good, but will check the chemical levels again tonight.