Only My Tiger Barbs are Dying?

[Byron]

I've plugged this YouTube channel before and didn't have it removed so I will do so again. A YouTube channel called aquarium coop has a series of I think 5 videos called "Plants 101" it's a very good channel targeted towards beginners and I think you would find the particular series listed above very helpful to you.

If you can make it through even one of these videos without falling asleep, you're doing well. If you listen to what he says, I would be careful. There are definitely some inaccurate bits, and some confusing info. No need for me to say more, as you were just asking about info sources, and while watching all these might give you some info, it can be much, much simpler. Decide what you want first, then look to the method.

Byron.

 

[AnnAlfie]

As the title suggests I have a community tank but only my Tiger Barbs are dying. I woke up this morning and everything seemed fine, an hour later 2 were dead, 1 died this afternoon, and 1 died this evening. Does anybody have any idea what could affect my tiger barbs only?

So you have a bit of background, it is a 40G tank with 2 Penguin 200 HOB Filters that has been established for 9 months with the following list of inhabitants for the last 7 months:

• 5 Tiger Barbs (Now down to 2)
• 2 Green Tiger Barbs (Now down to 1)
• 4 Santa Claus Swordtails
• 2 Dalmatian Mollies
• 1 Otto Catfish
• 1 Albino Rainbow Shark
• 3 Mystery Snails

Decorations include

• 8 "trees" of Water Wisteria
• 1 Moss Ball
• 20+ Branches of Cambomba
• Driftwood and Stones

They have all lived peacefully with no aggression between species since setup. I do 3G water change 5 days a week and clean the filters in old water once every two weeks. I also dose the tank with Seachem Flourish once a week and Seachem Flourish Excel once a day for the plants. The current water parameters are.
PH: 7.8 (my tap water is this high, I tried lowering it but that kept killing fish so now i leave it)
Ammonia: 0.25 PPM (usually 0 but i blame the dead fish that had probably been in there for a few hours)
Nitrite: 0 PPM
Nitrate: 5 PPM

Further note, I changed my substrate from a blue gravel to a black gravel for aesthetic reasons 2 days ago, the fish were removed and placed in 3 separate buckets while doing so (the barbs were in their own bucket).

So sorry to hear about your fish dying. Years ago I lost a veil tail angelfish that I'd had for 4 years. It's upsetting. I was thinking about getting a rainbow shark myself and what I discovered is that they can be very aggressive and territorial especially as they get older. Might be worth watching the little guy. I have green barbs also. They are beautiful fish. I hope you solve the problem. All the best

 

[StevenF]

My reasoning is that my available tap water sits at a pH of 8.0 and thanks to driftwood, my tank is usually around 7.5. I was afraid of doing larger water changes and socking the acidity of the fish. Any recommendations?

There is another explanation for your PH drop. Drift wood normally reduces PH by releasing tannins which are acidic. The tannins counteract the High ph resulting in a lower PH. However drift wood has fixed amount of tannins in it. Bacterial and water changes also reduce tannins.

The other way PH can be lower is by plants absorbing potassium, calcium and magnesium. These elements are typically the main causes of a PH over 7. All are nutrients plants need. As the plants remove them from the water the ph will drop. CO2 will then push the water PH down. By limiting your water changes you are preventing the water change from adding too much potassium, calcium, and magnesium.

I don't know which is dominating your tank. We don't know if your drift wood is still releasing tannins. There is no way to know with the information we have.