6 Dead Fish - 3 Left And Not Doing Well - Help!

[amie-t]

[SIZE=medium]Hi, [/SIZE]
[SIZE=medium]I am hoping that someone can help me.  I’ve lost 6 fish in the last few days and several of them I’ve had for over 3 years.  [/SIZE]
 
[SIZE=medium]Here are the tank details: [/SIZE][SIZE=medium]29 gallon, 3 years old but several fish were transplanted from a smaller tank that was about 2 years old.  I had 9 fish total and now am down to 3- one is a large parrot fish, another is a pretty large striped fish that I haven’t been able to identify (about 4 inches long) and a very small algae eater.[/SIZE]
 
[SIZE=medium]I went away for the Thanksgiving holiday and left 2 food disks in for the fish.  I always use the small tetra weekend slow release disks and haven’t had a problem in the past.  When I came home after 4 days, 4 fish (2 catfish, 1 sucker fish, and 1 tiger barb) were floating at the top and the food disks were not touched at all.  It looks like the fish were dead for some time – the water was very cloudy.  The remaining fish were mostly laying on the bottom not moving.  The parrot fish had visible discoloration (dark marks).  I immediately removed the food disks and dead fish.  I tested tank levels and nitrate and ammonia were at 0, pH was lower than 6.0 (normally the pH is 7.4), and phosphate was at about 3-4 ppm.  I immediately did a 50% water change and added tap water (tap water pH is about 7.4 and phosphate is 4.0ppm).  In the last 4 days, I've lost 2 other fish (1 large parrot fish) and have done two 25% water changes.[/SIZE]
 
[SIZE=medium]Last night, I did another 25% change, removed a large piece of driftwood that’s been in the tank for 2 years (I read that it can cause drops in pH), and added a pH stabilizing powder to try to fix the pH. [/SIZE]
 
[SIZE=medium]Here are the current chemical levels after the changes last night:[/SIZE]

• [SIZE=medium]Amonia – 0 ppm[/SIZE]
• [SIZE=medium]Nitrate – 0-2 ppm[/SIZE]
• [SIZE=medium]pH – 6.4 - 6.5[/SIZE]
• [SIZE=medium]Phosphate – higher than 10 ppm (this is the highest I’ve ever seen it)[/SIZE]

[SIZE=medium]The parrot fish is severely discolored and has been twitching.  For the last few days, he’s been sitting at the bottom of the tank and today, he’s been staying at the top.  The large striped fish has some red coloration around his fins.  Neither have been eating.  [/SIZE]
 
[SIZE=medium]Does anyone have any suggestions for ways I can save these fish?  They still look very bad but are a little more mobile than yesterday.[/SIZE]
 
[SIZE=medium]Thanks for your help![/SIZE]

 

[Ch4rlie]

Seems quite unusual. Sorry for your losses

First thing comes to mind is you had some sort of pH crash. The sudden swing in pH may be a big factor in your losses. The cloudy water suggests you may have had a mini cycle.

The Tetra food disc probably did play a part but not something I would have expected really since you mentioned you've used it in past. Unsure really. Not something I know much about TBH.

You make no mention of nitrite levels. Fish at water surface suggests possible nitrite / ammonia poisoning, along with red colorations.

I'd suggest you carry on keeping a close eye on water parameters and do water changes accordingly.

Also may be an idea to test your tap water to see if any changes.

Sorry can't be of more help at the moment

Hopefully someone a bit more knowledgeable may come up with more ideas soon.

 

[Blondielovesfish]

What test kit are you using?
Do you know what the nitrite levels are?
 
What was the exact stocking before your deaths?

 

[Xzavier247]

I had the same incident happen too. I bought Tetra Vacation. We put it in the tank the night before we left to see how it would react....... The next morning the water was cloudy and most of my stock was depleted....... I will never buy vacation feeders ever again. And I will have someone feed them while my wife and I are away.
Here is the link to my thread. Sorry for your loss. 
 
http/www.fishforums.net/index.php?/topic/426352-getting-back-into-the-hobby/

 

[amie-t]

Thank you for the advice.  I hadn't tested nitrite levels before but bought a test kit yesterday and the level of nitrite was 0.  Yesterday, I did a 50% water change and this morning tested the water.  All levels were the same as my original post except pH - pH has dropped back down to 6.0.  pH and phosphate are the 2 areas that are not in the recommended range.  (phostphate is 10.0ppm or higher) 
 
I put conditioned tap water into the tank after the water change - the tap water pH is 7.0 and phosphate is 1.0ppm. However, even after a 50% water change, the pH in the tank is 6.0 and phosphate 10.0ppm.  Is it possible that something in the tank is affecting the levels?  I also read that high phosphate can reduce pH - should I consider filter media to remove phosphate?
 
To answer the questions about the test kit - I'm using API liquid test kits for each of the different items.  Regarding exact stock prior - 2 parrot fish (both have since died), small algae eater (very small, not sure what it is but we've had it for 6 months), unidentified large striped fish (about 4 inches long and has been alive for 3 years), 1 tiger barb (had this one for about 2 years), 1 cichlid (had this one for about a month), 2 catfish (had these for 4 years and 2 years), 1 sucker fish (had this one for about a month).
 
Thanks again for your help!  I'll also read the post about the tetra feeders to see what I can get out of that.

 

[Meeresstille]

I suspect your pH is lower than the reading of 6 that you're getting, and if a 50% WC does not bring it higher than 6 that would explain why it won't show higher. You may need to do daily 30% water changes to bring the levels slowly up again. Be sure to do good gravel vacs since uneaten food and fish waste can cause pH crashes if you have soft water with low buffers.
 
Someone please correct me if I'm wrong but as I remember you could try adding crushed coral to your filter to raise the buffers in your tank water, this can help prevent future pH crashes.