Question About Disinfecting Tank and Filter

[kc27]

I purchased a used 55 gallon tank and a used Eheim 2028 filter. The tank is filled with water and gravel, no fish or plants. I am considering adding bleach in a ration of 20:1 (water/bleach) and let the filter run for a couple of days in order to disinfect the system. My question is: would doing this ruin the Substratpro and Eheim Mech filter media? The tank is not cycled, so I am not concerned about losing any biological filtration.

I am considering doing this because originally I cleaned the tank and filter with hot water and vinegar. I actually soaked the filter baskets and hoses for 24 hours in 100% white vinegar to remove some deposits. I then added new gravel and new media to the filter. The tank was filled, I added dechlorinator to the water, and let the filter run for a day, and added five 1.5" - 2" goldfish. Prior to that, the goldfish had survived (endured?) for 7 months in a 3 gallon unfiltered plastic tank (with frequent water changes).

All five fish were dead within two days. The fish store tested the water from the 55 gallon tank and didn't find any problems. However, I've been told that while the tank and filter were cleaned with the hot water and vinegar, they were not disinfected, and that something may have come along in either the tank or the filter and killed the fish.

So I am looking at adding the bleach to the tank and running the filter for a day. I just would like to know if doing this will make the filter media unusable.

Any thoughts on this?

 

[mfdrookie516]

vinegar has worked just fine for me. i used it to clean 3 or 4 tanks i've gotten from craigslist. The reason the fish died is because the tank wasnt cycled or you didnt rinse the vinegar out well enough more than likely...

 

[HN1]

I'm actually guessing that they died from LACK of nitrate.... OTS.

As MFD said, vinegar is perfectly safe. I've used it on dozens of tanks without a problem. How ever you clean it, make sure to properly cycle it before you add fish or all you'll get is more frustration and dead fish.

 

[kc27]

Would a 3 gallon plastic tank that had did not have a filter or gravel, and got a 60 - 80% water change every other day. be considered cycled? I never tested the water, but it doesn't seem as though it could have ever been cycled under those conditions.

HN1, are you saying the water in the 55 gallon tank was too clean?

 

[melosu58]

I`m one of those that use bleach and water. I use a couple caps of bleach to a bucket of water. Rinse real good and let dry completely. If it makes you feel better than when you put water in the tank add some dechlorinator but it`s not necessay.

 

[kc27]

Does using bleach ruin the filter's media? I know any bacteria on the media will not survive, but can the media be rinsed and reused?

 

[melosu58]

I would not run the filter with that Just clean the tank good and let dry. If you want to clean the filter let it soak in vinegar/water solution.

 

[jsoong]

HN1, are you saying the water in the 55 gallon tank was too clean?

He was being cryptic ... the OTS at the end of his post means Old tank syndrome.

That happens when fish lived in terrible water conditions, but got used to very high nitrates, & other dissolved organic stuff. <They can be living in water with so much stuff that the osmolarity approaches seawater.> When you dump them into clean water, the sudden shift in osmolarity caused their demise. When shifting fish from really polluted tanks to clean, you need careful acclimatization to allow the fish to adjust to the very different water parameters of the clean water.

If the fish died from OTS, then it is unnecessary to disinfect the new tank. I am doubtful that there is anything biologic in a tank that is completely dried that can kill fish like that. Pretty much all the aquatic pathogens are dead without water after a few weeks. If you really want to be safe, bleach is OK, but make sure you really rinse everything out well (with double dose of dechlor) to get rid of the bleach.

One possibility is chemical contamination. If the tank got exposed to pesticides or other chemicals during storage, there might be enough stuff leftover to kill fish. You can usu. rinse off chemicals in non-porous surface. But porous surface - like activated carbon, maybe some sand & lava rocks - may bind to the chemicals & resists removal .... causing fish death. A lot of people will ditch old media & substrates for this reason.

 

[jsoong]

Does using bleach ruin the filter's media? I know any bacteria on the media will not survive, but can the media be rinsed and reused?

Depends on the media - I tried bleach on filter foam & it dissolved & formed a gooey mess. My Magnum water polishing filter specifically ask for bleach when cleaning & I have done that without problem. Of course you can bleach bioballs & other "plastic" media. But do note that bleaching will kill the bio-filter ... but that wouldn't be a problem here as I assume the tank is not yet cycled.

 

[HN1]

Would a 3 gallon plastic tank that had did not have a filter or gravel, and got a 60 - 80% water change every other day. be considered cycled? I never tested the water, but it doesn't seem as though it could have ever been cycled under those conditions.

HN1, are you saying the water in the 55 gallon tank was too clean?

Yes. Jsoong explained it even better than I could have. I suspect OTS as the killer, but contamination is entirely possible as well. Sorry for being cryptic.

 

[kc27]

It sounds like I should have tested the water in the 3 gallon tank to get a baseline of what water conditions the fish were accustomed to before moving them. I am going to cycle the tank and try again with a couple of fish to see how it goes.

Thanks to all for the information and suggestions.