Strange swimming pattern in new tank

[Roland6543]

Hi all,

So I just set up a 70g freshwater tank. After a day settling in (I added the appropriate quantity of dechlorinator, plus some salt for freshwater tanks), I decided it time to buy some hardy fish to begin the cycling process. I put in 3 Zebra Danios (they came with a second, smaller tank I bought), plus 4 new small Danios and 4 Tiger Barbs that I bought from a big box store.

On the way home from the store, one of the new Danios was swimming in a crazy corkscrew pattern. By the time we got home he was swimming normally again. Stress I thought. We acclimatized the fish to the new temp by floating the bag, then added some water from my tank to their bags in two stages, then finally netted them out and popped them in the tank.

Within 6 hours 1 Danio was dead, and another was also doing the corkscrew olympics, and shortly also dead. I took them out. By the next morning of the 2 remaining newly purchased Danios, one was missing (half of him showed up later in a Barbs mouth), and another spiralling out of control (which I euthanized in the freezer).

I figured a bad batch of Danios from the store, since the 4 Barbs and the older Danios were doing fine. To get back to the original planned stock level I went to a different specialized LFS and bought 3 more small Danios. By the next day one of the new Danios from the small LFS is showing the same symptoms.

My tank is obviously still in the early stages of cycling. Results are:
Day1 Day2 Day3
pH 7.4 8.0 8.0
NH3 0.10 0.10 0.10
NO2 0.00 0.25 0.00
NO3 0.00 0.00 0.00

I'm thinking one of the following could be happening:
- The chemistry in my tank is causing this (Unlikely because the first symptom was on the way back from the pet store).
- Both stores that I bought the Danios from bought them from the same supplier and they are carrying the same "issue".
- The 4 small Danios that I bought from the big box store brought in a disease that is beginning to spread to the other Danios (the 3 older Danios are still doing OK).

What do you think? Any suggestions on how to deal with this?

[Honey Badger 1]

Here is something for you to read which may be a possibility of what is wrong with your fish.

http://www.wetwebmedia.com/fwsubwebi...irldisfaqs.htm

Most lfs get their fish from the same suppliers.

[Cermet]

Your water may be soft causing the pH drift and/or the substrate is causing the increase in pH. Test the substrate with vinegar - if it fizzles, it is not acceptable. Consider a hardness test kit. As for treating the fish, read the section on sick fish and post there as well.

[roma0]

I don't know much about the swirling but the only suggestion I can tell you from experience is that you should cycle your tank before adding fish... it takes about 2-3 weeks and it will save you a lot of head aches (all your fish might die in an un-cycled tank.

Browse the forum, there are many threads explaining the cycling process.

[Roland6543]

Thanks for the suggestions. I think I'll look into a hardness kit. Should I consider a buffer to reduce the pH, or leave it alone for now?

[Roland6543]

Question: If the hardness is high, causing the pH to rise, what can be done about it?

[Honey Badger 1]

If there is something in the tank making the ph change then remove that item. I have never had ph fluctuate drastically for no reason. It's usually caused by certain rocks or ornaments in the tank or a change in the water supply among other reasons. If the ph is stable I wouldn't mess with it. It is usually agreed that stable ph is better than the correct ph, unless it is so low it kills the beneficial bacteria needed to keep the cycle. I don't think it's the ph causing your problems because the fish started showing signs of illness before you even put them in your tank, but it is still good to know the GH, KH, and pH of your tank and tap water.

[Roland6543]

I have 2 friends in my immediate neighbourhood that set up tanks a few days before mine. Although they used a bacteria supplement and Seachem Stability (I didn't - I used Nutrafin AquaPlus only), they also saw a rise in pH of approximately the same amount in the first couple of days, then it stabilized at about about 8 (the same as mine). We are all using the liquid API test kit too, probably the same batch since we bought it from the same store at approx the same time. Perhaps we have something in our source water that causes an initial change like that. We all have different gravel and decorations. Another thought, perhaps we should take a sample of water into the store to double check the API test kit.

[Honey Badger 1]

The pH in a cycling tank is rarely stable and often fluctuates a bit until the tank is nearly cycled.

[Goes to 11!]

The pH in a cycling tank is rarely stable and often fluctuates a bit until the tank is nearly cycled.

+1

I wouldn't even bother checking the pH of a cycling tank, It rarely brings results that have anything to do with where it ends up [When cycled] and it's wasting time and a test imo.