Fish darting and water chemistry problems

[Axilleus]

1~What type of fish is afflicted? My black-skirt tetras are darting around the tank, but I can't tell if they are in distress or just harassing one particular fish. The fish that seems to be a target is hiding at the bottom of the tank and not moving unless chased. The others do seem to be swimming a little frantically when not chasing it as well, though.


2~What are your tank parameters (ammonia, nitrites, nitrates, temp, pH)? Please give exact values.

I had not done a water change for a month, and last night I did a 40% one. This morning, I tested and found that my tank seems to have uncycled itself in the last month. There was .5 ppm ammonia, 0 nitrites, 0 nitrates. In addition, when I checked my tap water which used to contain .25 ppm ammonia, it now contains 1 ppm ammonia.

3~ How large is the tank? How long has the tank been set up?

The tank is 30 gallons and has been cycled for 6 months.

4~What type of filtration are you using? Please give the name and number (i.e. Fluval 304) and amount of gph if known.
I have a 40-60 gallon Aquatech filter.

5~How many fish are in the tank? What kinds of fish are they and what are their current sizes?

I have four one-inch cories, six one-inch black-skirt tetras, and two three-inch Chinese algae eaters.


6~When is the last time you did a water change and vacuum the gravel? How often do you do this? How much water do you remove at a time?

Generally I do 30% water changes every two weeks. I did not do a water change for a month, and then I did a 40% water change last night. I have not vacuumed the gravel at all before yesterday, because I was trying not to disturb my plants (about 15 Java ferns). I also changed the filter cartridges.

7~How long have you had the fish? If the fish is new, how did you acclimate it/them?

I have had the cories and tetras for six months, and the chinese algae eaters for three months.

8~Have you added anything new to the tank--decor, new dechlorinator, new substrate, etc.?

While I was vacuuming the gravel last night for the first time, I turned over some gravel that was grey/black, whereas the rest of my gravel is tan. I think there may have been anaerobic bacteria growing in the lower parts of my gravel, and I turned some of it up to the surface. When I looked this morning, the black had disappeared from the gravel. Is it possible that when I stirred it up I released hydrogen sulfide and harmed my fish?

9~What kind of food have you been feeding your fish, have you changed their diet recently?

I was feeding Omega One freshwater flakes and algae wafers and API shrimp pellets, but for the past two days I've switched to Tetra Veggie algae wafers.


Summary all together: I did a 40% water change last night after not doing a water change for a month. I also changed the filter cartridges, but left the sponges in the filter. Generally I do water changes every two weeks. I also vacuumed my gravel for the first time ever, and turned up some blackened gravel, which, when vacuumed, gave off the smell of rotten eggs. I suspect it may have been anaerobic bacteria that I turned up. Now my tetras are darting around the tank, in particular chasing one tetra. Are they ill?

My water chemistry is also worrying. I have .5 ppm ammonia, and 0 nitrites and nitrates, so the tank seems uncycled again. There is also 1 ppm ammonia in my tap water.

1. Is there anything I can do to remove the ammonia from the tap water?
2. Would it help or hurt to do another water change at this point, and how much should I do?
3. How should I deal with the anaerobic bacteria in the gravel, if that's what it is?
4. I also have a bottle of Safe Start that I used to speed up my cycle the first time. Would it help the tank re-cycle quickly if I add that, and would that help my fish's symptoms?

Thanks!

 

[Delapool]

1. Is there anything I can do to remove the ammonia from the tap water?
2. Would it help or hurt to do another water change at this point, and how much should I do?
3. How should I deal with the anaerobic bacteria in the gravel, if that's what it is?
4. I also have a bottle of Safe Start that I used to speed up my cycle the first time. Would it help the tank re-cycle quickly if I add that, and would that help my fish's symptoms?

Thanks!

Hi, I think you have answered your own questions and know what you are doing - imo water changes should be 25 to 50% per week. But your tap ammonia is a problem. You would have to do small, regular water changes.

Water conditioners like seachem prime will make the ammonia safe until the bacteria can consume it. The water conditioner must say it makes ammonia safe, not all do. Just checking but tap is 1ppm for sure? Just seems high.

Do you have ph? Below 6.5 the bacteria slow down. The gravel vac may have stirred up rotting gunk and not helped but unlikely to be anaerobic bacteria unless your gravel is (from memory) more than 5 inches deep.

I'd say its the large water change with tap ammonia that is causing all the issues. Possible the water change shifted ph (and others like kh, gh) which the fish may not have liked.

Safe start is worth a try. Do you have any plants? Nitrates at 0 seem very odd. Did you clean filters recently?

Edit - just saw the filter change. Can you give more details on what is in the filter? Is there any biomedia of ceramic noodles? Sponges will hold some bacteria but ceramic biomedia has more surface area.

 

[Axilleus]

As far as the ammonia, I mentioned it to my local fish store manager, and he said the he knows that there is ammonia in the town's water. I'm not sure if the test was accurate, but I did it twice and it was definitely READING 1 ppm (API test kit).

I just have a sponge plus the filter cartridge, and I thought that since I didn't thoroughly vacuum the gravel and I left the sponge in it would be ok. I guess I may have been wrong.

I do have plants: about 15 java ferns. They aren't always very healthy, but they seem to die off and replace themselves such that the number keeps increasing and they keep growing.

I've always just not checked the ph (probably a bad idea I guess) because I heard it was worse to try to mess with the ph than to leave it the way it was. But when I actually did check, it raised questions about my test kit, because it tested both above 7.6 ph on the normal ph test, and below 7.4 on the high range ph test. Either way, it does seem like it might be high, though. If it is really that high, I'm impressed at how healthy my fish seem. I'll have to look into lowering the ph. The fish are acting normally now, however.

 

[Delapool]

As far as the ammonia, I mentioned it to my local fish store manager, and he said the he knows that there is ammonia in the town's water. I'm not sure if the test was accurate, but I did it twice and it was definitely READING 1 ppm (API test kit).

I just have a sponge plus the filter cartridge, and I thought that since I didn't thoroughly vacuum the gravel and I left the sponge in it would be ok. I guess I may have been wrong.

I do have plants: about 15 java ferns. They aren't always very healthy, but they seem to die off and replace themselves such that the number keeps increasing and they keep growing.

I've always just not checked the ph (probably a bad idea I guess) because I heard it was worse to try to mess with the ph than to leave it the way it was. But when I actually did check, it raised questions about my test kit, because it tested both above 7.6 ph on the normal ph test, and below 7.4 on the high range ph test. Either way, it does seem like it might be high, though. If it is really that high, I'm impressed at how healthy my fish seem. I'll have to look into lowering the ph. The fish are acting normally now, however.

Ph sounds good for bacteria. Mine is around 7.4 to 7.6 as well in the DT. I have neon tetras in a small tank at same ph.

It would be interesting to check tap water for ph and nitrates as well to see what you have. For ph check straight away and then let a jar of tap water stand for 24 hrs and retest - this will give true ph. I'll post a link later (unless someone has it) on ph vs ammonia/ammonium levels so you can see how much ammonia vs ammonium is in tap.

Most bacteria will live in the filter and on whatever has the greatest surface area. I would have some ceramic biomedia in there or a second filter. This is mainly so when you clean or replace the cartridge you don't have too much bacteria lost. Normally not an issue but as you have ammonia in tap you want the bacteria population as good as possible.

Then seachem prime will deal with tap water ammonia for about 24hrs. You look covered on plants which will also remove ammonia.

If you can keep ammonia down to 0.25 in tank it's not too bad at that ph.