hoppycalif

It is generally a good idea to use a dechlorinator when you add more than about 10% of new water. Almost all tap water has chlorine or a mix of chlorine and ammonia, chloramine, in it. Both are very bad for the fish if you don't add a dechlorinator that works with chloramine, with the new water very soon after adding the water. That would account for the small increase in ammonia in the water. (The dosage of dechlorinator needs to be based on the total water, not just the added water.)

Chris829

Yes this is a dirted tank and has been going since March. My Ph was about 7.6 before the change and the cardinals were Okay. I would say the change in PH is what did in the cardinals but they arn't the only fish effected. A few of my female bettas look like they are not feeling too hot and the vailed tail angel fish has a white film over his left eye. The other angels are fine. I did not disturb the substrate so I don't know why the ammonia spiked.

Chris829

I did use a dechlorinator/ conditioner (API tap water conditioner) that was for both chlorine and chloramine but your saying I should dose it based on 75 gallons instead of the 25 gallons changed.

Chris829

I'm using power head with a quick filter.

hoppycalif

As I understand it, the reason for dosing for the total water is to get the concentration of the dechlorinator high enough for it to be effective. So, I always dose for the full tank, and the bottle directions (Seachem Prime) say to do so.

EDIT: I googled a bit and found this in the Seachem website:
"Re: How much PRIME is too much?

Thank you for your questions. The standard dose of Prime (5mL per 50 gallons of water or 2 drops per 1 gallon of water) will only detoxify up to 1ppm ammonia.

It is completely safe to do a double dose of Prime in order to detoxify higher levels of ammonia. In fact, in emergency situations, up to 5 times the recommended amount of Prime is safe. In your case, when changing your betta's water, I would recommend adding 4 drops of Prime per gallon of tap water, in order to detoxify the incoming ammonia. As I said, this is very safe for your fish."

Chris829

Thank you Hoppy! I just just followed your suggestion and dosed the tank as recommended. I home that does the trick. In the future I will buy more jugs and age the water for a few days before I do a change.

mistergreen

You can also use vitamin C to neutralize Chlorine & chloramine. It doesn't neutralize ammonia leftover from chloramine though.
1/4 tsp per 100G will neutralize 1ppm of chlorine, which is how much most municipals add.

I run my tap water for the aquarium through a duel stage carbon house filter. It takes care of any chemicals. I tested how efficient it is and used the water on my daphnia tank. The daphnia survived.

hoppycalif

You can get rid of chlorine by "aging" the water, but not the ammonia. The ammonia will remain there until you do something to remove or neutralize it. Since there is no harm done by using Prime or an equivalent dechlorinator, even with overdosing it, it makes the most sense to forget the "aging" and always use the dechlorinator. As I understand it, aging doesn't help at all in getting rid of chloramine. In fact, the reason chloramine is so superior to chlorine is because of its stability.

mistergreen

Check with your local waterworks if they use chlorine or chloramine. You can usually find a water report on their website.