What causes ph shift

[robo-snickers]

Hi, so a few days ago half my tanks population was whipped out, killing off all my guppies and pygmy corys, (most of my plants are dieing as well) all i have left is an oto, 6 neons, and a ram... Ram isnt looking to good buy he is hanging in there. This massive die off happened in a little over 24 hours, as of right now im trying to investigate the cause of why this happened.

I came to the conclusion of it being the ph, mainly because my tap is about 8.4 and my tank was at a 6.2ish. Sadly im not aware of my tanks ph before the die off, however it seemed to be in harmony for the 8 months it has been running. Well before the die off i had a huge ammonia spike which i beleive had to do with me buying an upgraded filter, i used the same pads as my last filter but i think my other filter had alot of bacteria on the walls which i no longer had so it shocked my tank. The massive spike led to a nitrite spike and then everything settled and my tank was fine once again. 0amn 0nitrite 20nitrate. Well then the next day the die off happened. I checked the ph and found it extremely low. What could cause this massive change? Only think newly added was the filter, and what corrective action could i take?

 

[Rivercats]

First do a 50% WC now. You also said the day after the die off your tank ph was low, how low?

The one thing you didn't say was how often and what percentage of water do you change? As tanks age Ph tends to drop, if you don't do water changes your not adding any new buffers into your tank water. Your KH and GH are probably 0 also. You need to do Ph checks on your tank water even if your tank seems fine. Doing a 50% WC weekly will keep you tank better stablized. Fish and plants can both die if ph drops too low.

 

[Bbarb27]

Cycling a tank (growing colonies of benecial bacteria) can reduce buffers and drop your PH. If you recently had an ammonia spike followed by a nitrite spike, your new filter has cycled (a "fish in cycle" in this case) which is likely the cause of your rapid drop in PH. As the previous poster indicated, water changes can help avoid ph drops.

I'm sorry you lost so many fish.

 

[robo-snickers]

First do a 50% WC now. You also said the day after the die off your tank ph was low, how low?

The one thing you didn't say was how often and what percentage of water do you change? As tanks age Ph tends to drop, if you don't do water changes your not adding any new buffers into your tank water. Your KH and GH are probably 0 also. You need to do Ph checks on your tank water even if your tank seems fine. Doing a 50% WC weekly will keep you tank better stablized. Fish and plants can both die if ph drops too low.

I normally did about 40-50% weekly, however before i got the new filter i noticed small traces (.25ppm) of amn in my tank (which prompt me to get a new bigger filter for a large bacteria colony since i was worried the amn wasnt being broken down fast enouph), and found out my city water had 1-2.0 ppm of amn. Then i asked around on the forums and was told to do water changes about twice aweek but only do 10%. that lasted about 2-3 weeks before the die off. I also got my water tested at petsmart to get another reading besides my own and their test kits showed 0 KH (i beleive that what tge reading was) while my tap has i believe 150. Sorry im at work so i dont have the paper work on me.

 

[robo-snickers]

I have a small 10 gallon tank, could i move my fish into this tank with the same water as my 29 gallon and slowly work on changing the ph on that tank since itll be easier? While i replace the water in my 29G and work on cleaning all the dead snails (the small kind that comes on plants... They all died as well) and trim my dieing plants. That should reset the the ph, and once the water in the 10 gallon is good place the fish back? Should take more then a few days i think? Or is this a bad idea?

 

[Rivercats]

IMO I'd move the fish to the 10g using 2/3 29g water and 1/3 fresh tap. Also can you use some filter material or the old filter with current filter media on the 10g? Then I'd do small daily WC's to bring the ph up to an acceptible level.

As for the 29g, if all the live fish are out, I'd drain it down, remove all the dead/dying stuff, trim plants, and refill with fresh water. I would wait for at least a couple weeks to readd the fish and that would be only after the tank is reading 0 for ammonia and nitrites, and the ph is the same as the 10g. I wouldn't rush it. Then I'd do weekly testing on ph/kh/gh for awhile to be sure the tank is indeed stablized with your 50% normal WC's.

 

[robo-snickers]

IMO I'd move the fish to the 10g using 2/3 29g water and 1/3 fresh tap. Also can you use some filter material or the old filter with current filter media on the 10g? Then I'd do small daily WC's to bring the ph up to an acceptible level.

As for the 29g, if all the live fish are out, I'd drain it down, remove all the dead/dying stuff, trim plants, and refill with fresh water. I would wait for at least a couple weeks to readd the fish and that would be only after the tank is reading 0 for ammonia and nitrites, and the ph is the same as the 10g. I wouldn't rush it. Then I'd do weekly testing on ph/kh/gh for awhile to be sure the tank is indeed stablized with your 50% normal WC's.

Yeah my old filter was a marinland penguin 200, my new one is a 350, so the media is interchangeable. Do you think the massive change to the 29 will kill my remaining plants? And how often should i change the 10 gallons water to stabilize the ph?

 

[Rivercats]

IMO I think that is the best way to try to save the plants. If you don't feel comfortable with tha big of a water change I'd do at least 70-80%. Leaving them in that water is a death sentence. I don't know what kind of plants you have, you might expierence some melting but I think the plants will perk up. If you don't have a test kit you need to get one as you are going to want to keep tabs on the ammonia, nitrite, and ph in the 10g. Were it me I would just change out 2 gallons every day in the 10g to raise the ph alittle more gradually.