Swordtails spontaniously expiring

[psueric]

I am new to this forum, and the aquarium hobby in general, please forgive any mistakes/omissions...

I have a newly setup 55g aquarium, which has just completed its 4 week nitrogen cycle. I started the cycle with 6 1" zebra danios.
My tank has a Marineland C220 Canister filter, and a Marineland Penguin 350 Biowheel.

I am on well water, with a "whole house Neutralizer" which results in tap water with ph of 7.0.
After sitting for 12-24 hours, the Neutralizer wears off, and the water settles at 7.8. That's where my tank PH has been since day 1.
Because of this fluctuation, I try to limit my water changes to 20% once a week.

Ammonia is at 0ppm, and Nitrites also 0ppm. Nitrate is <10ppm Temp 81F

My current stock includes the original 6 Zebra Danios (1") 3 Gold Barb (2") 3 cory cats (2") and 2 african dwarf frogs (1")

3 days ago I added 4 Red Swag Swordtails (2 1/2" each)
1 male, and 3 females.

I used my standard method to acclimate these fish. I floated the bag for 20 minutes, then added 1/2c of aquarium water to the bag every 20 minutes for 2 hours.
I then netted the fish into the aquarium, discarding the water from the bag.

They swam happily for 3 days, and this morning, the male, and 1 female were dead on the bottom of the tank.

My feeding includes "TetraMin Pro" flakes, FreezeDried Blood Worms, and SunDried Baby Shrimp

All of the swordtails actively ate at feeding time.

I have read that the Swordtails are well suited for my waters PH levels, and that they are particularly hearty...

I'm just trying to figure out what might have happened to these 2 fish, and if there's anything that I can do to keep the other 2 from suffering the same fate.

Worth noting: one of my three gold barbs has developed a condition where he's not able to swim very well. He kind of drags his tail along the bottom of the tank, and seems to tilt from side to side. When this happens, he will sometimes dart around the tank. He doesn't seem to be eating very well (as opposed to the other gold barbs, who are extremely aggressive eaters) I have read that this could be related to his "swim blatter" and there's probably not much that I can do for him.

Could this "swim blatter problem" be related to the death of the swordtails?

Thanks for reading this far...I look forward to your comments.

 

[corster]

I'd stop messing with the PH, if your water has a lot of carbon in it and you lower or higher your PH your water will just go back or at another lever you don't want it to be at. Drastic PH changes can kill fish fast. Just use your regular tap water (if you live in the cite use water conditioner). Your lucky you have a PH of 7.0. My water around here is so hard 8.4 PH and a GH & KH of 250-300.

 

[fearlessfisch]

I think the OP meant that all the water for the house is treated that way, in which case the pH swings would be unavoidable.

What kind of test kit are you using for your water? Every time I have done a cycle from scratch, it has taken closer to six weeks. If you are using test strips instead of the more accurate liquid tests, it may be that you are getting inaccurate readings.

Also, are you using a dechlorinator that removes heavy metals?

It could be that you just got some weak swordtails, but the illness of the gold barb is concerning. Problems with water quality can be responsible for different types of symptoms in different fish.

I can't think of anything else offhand, but maybe someone else will come along with ideas.

 

[psueric]

fearless is correct about the "whole house conditioner"
I don't have an option to get "unconditioned" water, so the PH swing is going to be a problem.
I've resigned myself to max 10-20% PWC, to keep the PH Swings to a minimum.
They will have to be done more often, but with the Python, it's not too much trouble.

The other Swordtails are still doing well.
The gold barb didn't recover from his swim problems, and died a few days ago.

I'm not using a dechlorinator, because I'm using well water, which isn't chlorinated.
Is there still an advantage to the dechlorinator?

I'm using API test kit, and I've confirmed my results by taking a water sample to LFS.
All other fish are doing well, so I'll chalk it up to MFD.

Thanks for your help!

 

[fearlessfisch]

If you have this problem again and it occurs right after a water change, I wonder if it would be worth it to invest in a couple of large containers so that you can age water for a day or two before doing a water change.

Good luck with the tank. I'm glad the other swordtails are doing well, and sorry for your gold barb.

 

[psueric]

what about using a product like Proper PH8 to equalize the PH during the water change process?