All our guppies died

[howdyheidi]

My question is this. If we decide to keep fish again, should I completely clean out the tank and start over, or is there a way to figure out what was wrong with the water and fix it??? Thanks so much for any help.
______________________

We have a 10 gallon tank that is 18 months old. We only have kept guppies. We had 3 guppies at this time and I change 25% of the water once every 1-2 weeks. I test the water sometimes with the API kit and it read pH 7.6, Ammonia 0, Nitrite 0, Nitrate 20. The water temp is 79 and we match the water temp of new water pretty closely. We use API Stress coat and wait 10 minutes or so before adding the new water.

We have never had a major problem with the tank before.

On Wednesday, we added new plastic decor plants. We rinsed them really well before adding. We did a water change at the same time.

The orange guppy slowed down almost immediately and was dead by morning. He has had a "bubble" on his dorsal fin for several months and it never seemed to affect him. The yellow and blue guppies died then within about a day.

I really do not know what happened. It looked like what I read is ammonia burns, but I tested that over and over and the level was fine.

We do sometimes have a sulfur odor to our tap water, so I am wondering if that is what happened? I have used the same tap the entire time we have kept the fish.

If we keep the aquarium going should I switch to bottled water?

TIA.

 

[fishychick]

What did you use to rinse the new plastic plants? Plain tap water? Tank water? Dechlorinated tap water?


Sent from my iPhone using Aquarium Advice

 

[howdyheidi]

What did you use to rinse the new plastic plants? Plain tap water? Tank water? Dechlorinated tap water?


Sent from my iPhone using Aquarium Advice

Tap water

 

[fishychick]

Maybe they reacted to the chlorine in the tap water you used to rinse the plants? When I wash or rinse things I use tank water or dechlorinated tap water.


Sent from my iPhone using Aquarium Advice

 

[howdyheidi]

Maybe they reacted to the chlorine in the tap water you used to rinse the plants? When I wash or rinse things I use tank water or dechlorinated tap water.


Sent from my iPhone using Aquarium Advice

Thank you. That is definitely something I will do in the future.

I am hoping to rule out other issues as well.

I also am wondering if I should be testing the hardness of the water. The API kit I have does not include that. I am wondering if something changed in our city water that would be toxic to fish, or are so different from our tank water parameters. I do not know how often city water changes.

I am planning on stirring up the gravel and seeing if I smell any sulfide too (have been reading articles about what might be happening.)

 

[fishychick]

Thank you. That is definitely something I will do in the future.

I am hoping to rule out other issues as well.

I also am wondering if I should be testing the hardness of the water. The API kit I have does not include that. I am wondering if something changed in our city water that would be toxic to fish, or are so different from our tank water parameters. I do not know how often city water changes.

I am planning on stirring up the gravel and seeing if I smell any sulfide too (have been reading articles about what might be happening.)

You could search this forum for other threads where people have addressed water hardness issues. I have never really tested hardness. You could probably check with the city to see if they have had any changes or issues with water recently. You should probably test your tap water too, that will give you a sort of baseline to know what you are working with. My tap water has a little bit of ammonia to it right out of the tap.

 

[absolutangel04]

Your water sometimes smells like sulfer? That might be your issue.
Fish like guppies are not really too keyed in on the hardness of your water. Wild caught fish are more sensitive to water parameters like pH and hardness, but most commonly captive bred fish like guppies are highly adaptable to a very broad range.

 

[howdyheidi]

Thanks. The aquarium has never smelled like sulfer, but our tap water sometimes does. I didn't notice anything the day we did the water change.

Thanks for the answer on water hardness.

I have tested the tap water with the API kit before and didn't notice much. I probably will test it again just to see. I am working on it and will update.

Update:

The reading I provided in the OP were from Wednesday morning.

The readings I got today are the same, except the pH dropped to 6.4.

There are no fish in there, but I am wondering if that is indicative of my problem. I will be searching the forum and researching why this might happen. I have not seen big pH changes in the past.

 

[howdyheidi]

Maybe Old Tank Syndrome? Maybe I am not cleaning gravel deeply enough and stirred things up too much with the rearranging of plastic plants and it caused the pH to move around because it is unstable?

 

[doctordamen]

Check your KH range as well, a low KH can cause your ph to fluctuate easily. If it is below 4 than that is most likely your problem.


Sent from my iPhone using Aquarium Advice

 

[absolutangel04]

No, your tank is not old enough for that.
All your deaths happened at once pretty much. That generally means there was a problem introduced. Sometimes it happens from the tap water, or some other sort of contaminant. Maybe there was something extra on your plants.
Hydrogen sulfide is what makes that sulfur smell. I know other stories where that caused problems in tanks. Though, it is hard to say. You may want to look into the causes of that and consider your options. Though, you did say you didn't notice the smell. Like I said, my only other idea is that something came in on your plants. I can't think of anything that could have that effect though. Cleaning chemicals from someplace in their past? Any chance there was an overdose of the stresscoat?
Frankly, I don't know. Just offering the best ideas I have.

 

[doctordamen]

Sounds like your problem is 100% the ph swing to me... Going from 7.6 to 6.4 in a short time will definitely kill all your fish at once. Keep in mind the ph scale is a logarithmic scale. So a little change in ph is actually quite a lot for the fish.
Trying to find the reason the ph dropped is your goal, imo.
Check KH


Sent from my iPhone using Aquarium Advice

 

[howdyheidi]

Thank you very much!

I did not know that you could overdose on stress coat, but I don't think that is it. It is my kids tank, so yes, he sometimes overfeeds and maybe doesn't measure 100% correctly, but not ridiculously off and I also do a lot of it.

Well, the pH swing I saw was after the fish died, but of course, I haven't tested it in a while before Wednesday. Learned the less the hard way.

I think I will probably order the hardness test kit, just to satisfy my curiousity.

Should I switch to another source of water just in case the sulfur is a problem? (We think it is an older water heater that generates the sulfur sometimes and that isn't getting changed right away.) I have read that maybe bottled water is not the best either?

And do I need to sanitize the tank, or can I just do some cleaning and water changes and then make sure the levels are stable for a while and then get a couple fish.

Thanks again for the help.

 

[Matt68005]

Have you tried prime as your declorinator? It should neutralize heavy metals in tap water. You could also try to use a ph buffer along with the prime, like PH 7.0 so that it stays even. Volcanic rock is cheap and helps buffer ph. This is just my measly 2 cents worth....good luck. Guppies can be fragile when stressed or new..... god i know.
http://www.apifishcare.com/product.php?id=641#.VRRt2vnYVgg

 

[howdyheidi]

Thanks Matt. I have not tried Prime. When I set up the tank, we just used all API products. I have not figured out why people recommend Prime so much higher than the other brands, but I will look into it. API says that Stress Coat also neutralizes stuff, but maybe one does more than the other?

I decided that I will use cold water from the tap and heat it since the source of any sulfur would be in the hot water (hot water heater, city water).

I just got the kits to test for water hardness, but haven't had a chance to test it yet. Still considering that they died because of pH swing and/or something in the plastic plants I added.

I am going to work on the water more and then hopefully try and get two more guppies right after Easter.

Again I appreciate the replies.