I Think I Know Why I Keep Losing Fish

[goldfish98]

So, as most of you know, before this problem I had 3 platys, 1 swordtail, and an otto cat. It started when I put a moon rock in the tank. Before I put it in, the PH was 7. The next day, the PH was 6, and the fish were dead. I bet I had a PH crash. 

 

[eaglesaquarium]

That's a reasonable explanation.

The real question is: Why did the pH drop so dramatically and quickly.
 
 
You said its a 'moon rock'.  What exactly is a moon rock?
 
Next, how large and how frequently do you change the water in your tank?

 

[goldfish98]

http/www.amazon.com/Underwater-Galleries-BC084239-Glow-Moon/dp/B00BKB318Q
 
Thats what a moon rock is. Its supposed to glow in the dark. I do 10-15% changes weekly. 

 

[eaglesaquarium]

Sounds like that supposed to be inert.  Which means it wouldn't affect pH.
 
Which means the pH crash is more than likely due to insufficient water changes.  You didn't mention how big the tank is, but I'm going to guess that the nitrates are fairly high to very high and/or that your water is extremely soft.
 
 
The best remedy is to increase your water change size and frequency for a while... 20% twice a week for two months.  Then 25% weekly there after, mixing in a 50% water change at least every 6 months wouldn't hurt either.  The tank seems to be on the verge of, if not already in the midst of 'Old Tank Syndrome'. 
 
 
When water changing, you also want to be sure to do a thorough gravel vacuuming as well as this will remove detritus that will also produce ammonia, which eventually turns into nitrate - which leads eventually to the pH crash.
 
 
If you can test your nitrate and your TDS, that would be a good start to confirm that this is actually the case.

 

[goldfish98]

This was before I took down the tank and restarted. The tank isn't old, I got it less than a year ago. 

The tank isn't cycled yet. Didn't even start the process yet.

 

[DreamertK]

The tank isn't cycled yet. Didn't even start the process yet.

I think we found the problem right here.

 

[KirkyArcher]

Someone else posted on the forum about fish deaths after putting this "Moon Rock" in their aquarium!

 

[goldfish98]

Can I see the link if you don't mind?