I accidentally killed some of my fish!

[Herefishie]

I've only had my aquarium for less than one year and I just made a horrendous mistake. I always heard you could regenerate Purigen by soaking it in water and bleach. Well, I did so and then I rinsed and rinsed and rinsed until I was sure it was safe. I put it back into my filter and within 60 seconds most of my fish were racing to the top of the tank searching for air. I knew immediately what I had done so I pulled it out and did a large water change. Over the course of the next 12 hours I lost three of my neon tetras. I thought I was going to lose more as they didn't look so hot but they pulled through. 

I'm sharing this information for newbies like myself so they don't make the same mistake. I should have read the full instructions on how to regenerate. I feel bad but lesson learned. 😢

Edited November 7, 2023 by Herefishie

[TOtrees]

That's sad. Most folks here can be divided into one of a few groups: people who've made similar mistakes; people who haven't made similar mistakes YET, and people who have made similar mistakes but won't own up to it. 🙂 

So basically we're all in the same boat. 

You should be grateful the response was so immediate. If it had occurred 1 or 2 or however many hours later, you might never have seen it.

What would you do different next time? 

[Herefishie]

I can honestly say that after watching YouTube videos for hours on end, that is what triggered me to realize what had happened. Otherwise I would've just thought how cute that my fish were darting around. I have now vowed not to try to regenerate Purigen. I ordered some little bags and a container of it so I can just change it out each time and save a little money doing it that way as opposed to the individual prepackaged ones.  YouTube videos, especially those from knowledgeable fish keepers like Corey, has taught me so much!

[Galabar]

Just as an FYI, here are the Purigen directions:

https://www.seachem.com/purigen.php

Quote

Directions

Rinse before use. Use in a fine mesh (180 micron or less) filter bag such as Seachem’s The Bag™. For best results, Purigen® should be placed so as to maximize the flow of water through it. It may be used in a canister filter, media chamber, box filter, or any high flow area of a trickle filter. Each 250 mL treats up to 1,000 L (250 US gallons) for up to six months. Exhaustion is indicated by a pronounced discoloration of the beads to dark brown or black.

Regeneration

Soak in a 1:1 bleach:water solution for 24 hours in a non-metallic container in a well ventilated area and away from children. Use regular 8.25% hypochlorite household bleach (non-scented, no dyes, do not use a splash-less bleach). Rinse well, then soak for 8 hours with a solution containing 4 tablespoons of Prime®, or equivalent dechlorinator per cup of water. Rinse well. For freshwater use, soak for 4 hours with a solution containing 2 tablespoons of buffer per cup of water (Discus Buffer®, Neutral Regulator®). Original color and full activity should now be restored and Purigen® is ready for reuse. Caution: some slime coat products may permanently foul Purigen® and render regeneration difficult. Do not reuse if odor of bleach/chlorine is detectable. In case of doubt, soak beads in small quantity of water and test for residual chlorine with a chlorine test kit.

 

[Herefishie]

Thank you! Sadly, I found this after my mishap. This is all on me…

[lefty o]

pretty much everybody that keeps fish has killed some off due to errors. all you can do is not make the same error again.

[TOtrees]

On 11/7/2023 at 3:48 PM, Herefishie said:

I have now vowed not to try to regenerate Purigen.

For what it's worth, if you do it right (see below 😕), it works fine. I no longer run Purigen for other reasons (basically, don't need it), but when I did I had 2 pouches that I'd alternate between. I keep both Prime liquid and the powdered version (Safe) in my fish room (I went through a stage where I had to buy one of everything too), and mainly the only use I had for the powdered version was for dechlorinating things I'd bleached, including Purigen.

Although [does maths... type type... puzzler activated] now that I am running the numbers, it looks like I was under-dosing, somewhat. C'mon man! Practice what you preach already!

 A 1/8 tsp of the powder (the smallest measure I have) is good for a whopping 150 gallons at the regular tap chlorine rate. The instruction from Seachem above (thanks @Galabar) calls for 4 tbsp of the liquid, which translates to enough to treat 600 gallons. So even though I thought I was being excessive, I was actually using 1/4 the recommended rate. For this type of application, I don't think you get into issues unless you're off by 1 or 2 or more orders of magnitude (like a factor of 10 or 100), and like you I rinsed well to remove most bleach. I'd be willing to bet that Seachem's safety margin (how much they recommend over-dosing to ensure all possible scenarios are covered) exceeds the factor by which I under-dosed. Like I said I never had issues. 

See? Solid proof that we all make mistakes. 

[tolstoy21]

Soak the Purigen in Prime after the regeneration. This should neutralize the bleach. 

You may also be able to regenerate these in a brine solution, but I'm not 100% sure. 

When I used Purigen, the bleach soak + Prime rinse worked. 

[Chick-In-Of-TheSea]

One time I took some water out of my tank with a pump.  I shut the pump off then went outside to rinse/prepare sand substrate.  That takes awhile because sand can be dusty.  Came back in to a filter grinding dry and the fish were freaking out swimming in like an inch of water. omg - The tank gravity-drained...  the thing is, stuff happens...  I'm so sorry you lost fish.  I know that's not easy.  You did everything else right; you just missed one step.  It's easy to do, and could have happened to any of us.

[Herefishie]

On 11/8/2023 at 8:45 AM, Chick-In-Of-TheSea said:

One time I took some water out of my tank with a pump.  I shut the pump off then went outside to rinse/prepare sand substrate.  That takes awhile because sand can be dusty.  Came back in to a filter grinding dry and the fish were freaking out swimming in like an inch of water. omg - The tank gravity-drained...  the thing is, stuff happens...  I'm so sorry you lost fish.  I know that's not easy.  You did everything else right; you just missed one step.  It's easy to do, and could have happened to any of us.

Oh my goodness! That's quite a story. Making mistakes definitely teaches us what to look for and watch out for so we hopefully don't make the same mistake.