eddieperth

Quick update:

Switching to Prime and using the higher dosage has sorted things!  Thanks to all of you for the advice

One person asked about the age of the tank: It has been running for about 12months.

Would love to get recommendations for best canister filter media.

Also, the tank has consistently low pH.  While the fish seem just fine, I'd like to raise it a bit...would a small bag of crushed coral in the filter be the best way to raise it?

thanks again!

Thanks for all the additional comments since I last spoke up!

I'm still having the same issue.  I've basically been overcoming this by taking water from a plant only tank to fill the main tank, and then adding fresh water to this plant only system.  So it's not really fixing anything, but, the fish are unaffected.  I'd really like to get to the bottom of this!

Humbug, you're theory about Chloramine fits the evidence....but two questions:

1. How could I find out what my local Water Corp. puts in the water?

2. if it is Chloramine, how could I overcome this problem?

Jules,  I'll def try the method you describe and see if it makes a difference!

From what I understand, you top up the tank then add the water conditioner that has been mixed in a bucket... If this is the case, next time, try adding the required amount of water conditioner to the emptied aquarium before topping up with water. Also, if you are using a garden hose to top it up, flush the contents of the hose first before adding water to the tank (plasticisers in the hose can be toxic)
Basically, something toxic is coming through your tap water that is killing off your filter bacteria, causing a spike in ammonia or nitrite.... or so it seems.
So try to change the methods of your water change and see if that improves the situation.

You are definitely thinking along the same lines as me, Docfish!  Thanks for your input

I agree that it seems these major water changes are causing a bacteria die back.  After the latest incident, I've been monitoring nitrites and they were back to 0 within about 4 days, which makes me think that not all of the bacteria are dying, but enough to cause a spike.

I add the conditioner to the bucket of new water, just before putting it in the tank.  I figure that ensures it mixing well, and have never had issues with this method in the past.

Also, I don't use a garden hose, but fill buckets in utility sink.  I have been letting the tap run for 20seconds or so before filling.

I'm due to make another small water change today.  I have a small aquarium that I use for extra plants....I think I'll use water out of this tank to top up the main tank just to give the fish a break.

Silly question : try to smell your prime... does it smell bad?

Thanks Mattia....it smells fine. I didn't start using Prime until after the problem started

Tried running the same tests directly from the tap?  In some hotter months the water corp may draw from underground bores.

 

Seachem Prime may be of use to help neutralise the nitrite if it's intermittent.

Thanks Dazza! Yeah I've tested the tap water for Nitrites and pH. results are 0 and 7.0 respectively.

And yeah after the last time, I got some Prime to ease the impact on the fish.  I think for the next change I'll also draw the water a few days in advance...otherwise, I don't have any ideas