Fish good with high PH

[Jollyroger2]

So I got some fish last night for a new 20 gal tank, the cycle was good, PH is in the 7.9-8.0 area, ammonia is very low, 0 basically, maybe very slightly into the 0-0.25 ppm range. Nitrites and Nitrates are 0. I had the local aquarium store (a good store, not Petco, Petsmart, etc), a good aquarium only store with massive tanks on display, good stocks of freshwater fish, etc. test a sample and it was all good.

I bought six glowlight tetras and three cory catfish. I had asked the guy about green neon tetras but read they prefer lower PH like 6-6.5 and he said yes that's true. But he said the black neon tetras or glowlight tetras would be fine, although I questioned that as I read they're good up to 7 or a little higher, but wasn't sure about my 7.8-8 range. He said they should be fine.

So this morning one was dead, another swimming erratically and it died an hour or so ago. The other four seem ok for now and the three corys are fine. I tested the water again and got the same readings, same PH, ammonia, nitrites/nitrates, etc. I called the store and talked to a different guy who said any of the tetras probably would be better with lower PH and he suspected that's the reason they died. Hopefully my others won't go the same way but if so they'll refund me or give me other fish of the same value.

So, I'm thinking a good beginner fish for kids that likes PH would be something like mollies, platys, etc? Any other suggestions for non-aggressive fish that like that kind of water, our water is overall "hard". I've read up on this alot and have a few ideas for something simple but wondered if anyone else has any suggestions. Nothing too pricey yet or fin-nippers, etc. Thanks!

 

[JuiceBox52]

What's your GH. In numbers as water companies will often call hard water soft and soft water hard. Gh is more important than ph

 

[TetraMan2007]

I’m actually not sure what has killed your fish. Tetras are normally pretty adaptable. I have 6 neon tetras myself and have them in some soft water, but my PH is higher then what they prefer. A little over neutral (7). I have had them for three months now and they are all doing fine. I’m not sure why your fish died. What type of acclimation did you use? Sometimes a sudden change of water parameters can cause stress and kill.

 

[Naughts]

Did you cycle your tank? If yes, which method did you use?

 

[Metalhead88]

Did you cycle your tank? If yes, which method did you use?

This. Care to elaborate? How long and how did you cycle?

 

[Colin_T]

Don't add any new fish until your current ones have been good for at least 2 (preferably 4) weeks.

 

[Jollyroger2]

Did you cycle your tank? If yes, which method did you use?

Yes the fishless cycle, all the numbers were good for over a week. Also had the water tested by the aquarium store and all was good.

So far none of the other tetras have died. Ended up getting some platies today and they seem to be doing fine as well, will keep an eye on them all.

 

[Naughts]

You're tank will not have cycled in just a week. Read up on cycling in the beginners section. It is a process that can take 6 weeks or more.
You need to do a 75% water change straight away as there could be toxic ammonia in the water.
Then get a test kit and check the ammonia and nitrite levels daily. Any day that the readings are not both zero, do a big water change.

 

[Essjay]

As a point of clarification, cycling is not just letting the tank run, it is the process of growing bacteria to deal with fish waste, specifically ammonia. These bacteria are slow growing and can take a couple of months to grow enough to deal with the ammonia from a sensibly stocked tank of fish.
A tank can be cycled in a few ways -
fishless cycling, by adding ammonia to grow the bacteria before fish are put in the tank
fish-in cycling, where fish are used as the source of ammonia
silent cycling, which is using plants to remove the ammonia

It sounds as though you are now doing a fish-in cycle, which means you must do lots of water changes to keep ammonia and later nitrite as close to zero as possible. Adding Tetra Safe Start will help as this contains the bacteria we need, though it won't work instantly, you still need to keep an eye on the levels and do water changes when necessary (ie ammonia and/or nitrite above zero)
Getting live plants will help too, especially floating plants.


When the water was tested it would have been good as there were no fish in the tank yet to make it not good.

 

[Jollyroger2]

You're tank will not have cycled in just a week. Read up on cycling in the beginners section. It is a process that can take 6 weeks or more.
You need to do a 75% water change straight away as there could be toxic ammonia in the water.
Then get a test kit and check the ammonia and nitrite levels daily. Any day that the readings are not both zero, do a big water change.

Sorry, I wasn't clear. I'm not new to this. I had a 60 gallon tank for many years but gave it up when I had twins. It's been about ten years and am getting back into the hobby so I got a 20 gal tank for the kids to work with. I have changed the water already a couple times during the process, it's been more than a week, and I have a test kit and have been checking it daily, everything is good. I also have taken water samples both to Petsmart and also a high end aquarium-fish only store and they've tested the water and all the readings have been good.

The explanation I've gotten from the aquarium store and also a couple friends who have tanks is that the glowlights were wild-caught and probably even more sensitive to the higher PH. This morning the others are doing ok as are the new platies, will keep seeing how things are going.

 

[Byron]

Yes the fishless cycle, all the numbers were good for over a week. Also had the water tested by the aquarium store and all was good.

So far none of the other tetras have died. Ended up getting some platies today and they seem to be doing fine as well, will keep an eye on them all.

What is the GH (general hardness) of your water? This was asked previously but not answered, and you now have fish that have differing requirements.

The explanation I've gotten from the aquarium store and also a couple friends who have tanks is that the glowlights were wild-caught and probably even more sensitive to the higher PH.

It is highly unlikely that glowlight tetras available in stores in North America will be wild caught fish, unless the local store imports direct from South America (few do, unfortunately). They still need softish water, but this does not mean soft or very soft, but fairly hard water will not suit them. Livebearers like the platies do need moderately hard or harder water, or they will not be able to function properly.

 

[Metalhead88]

But aside from letting it run, what everyone is asking is exactly what did you do to cycle the tank? How long has this tank been set up?

I can test my tap water right now and it will be safe for fish based on a test kit. That does not mean I can put my fish in tap water and add some water conditioner. They will be ok for a bit because the water is good.....but it will not stay that way. Without bacteria, ammonia will build fast and all fish will die. You need that bacteria that lives in your filter and on all surfaces of the tank to keep ammonia levels at zero.

Any amount of ammonia reading leads me to believe that this tank may not be cycled. Do you have number results of nitrite and nitrate?

The fish likely did not die from your pH levels. If fish are in the wrong GH or pH levels, they will die over time. Not fast.

What glowlight tetras are we talking about? If you have these guys, they may be wild caught.

The neon colored ones that glow under a blacklight (Glo Tetra) are highly unlikely to be wild caught.

 

[I nEEd mEnTAl HeLP]

I find it kinda hard to believe your ph is what killed your fish. Fish are usually pretty adaptable. What are your exact readings? And how does the tank have 0 nitrates if its cycled? Also, I believe you said there were traces of ammonia(although that could be a false reading)?

 

[JuiceBox52]

A cycled tank can have 0 nitrates if it is lightly stocked and has a good number of plants. Also if there are large water changes

 

[I nEEd mEnTAl HeLP]

A cycled tank can have 0 nitrates if it is lightly stocked and has a good number of plants. Also if there are large water changes

I know, I was curious since most tanks have nitrates.