Starting Over...

[jbliss145]

Hello! I'm new here but not terribly new to keeping fish. I have had a 20g tank for about 7 years. After cycling, the tank was stable and great for years. A few weeks ago I added a few fish from a LFS and that was the end of my tank. I should have known better than to not use a QT. Every fish I had died from who knows what. They didn't look ill, no white spots, no visible signs, nothing. Every day I'd find three or four more dead fish. Water parameters were good, so I'm completely stumped.

After gutting the tank and cleaning and disinfecting everything, I've got the tank setup and ready to start the whole process all over again. I've got two filters running now, a Fluval C3 and an Aqueon Power 20.

My question is this: In the future, once the tank is cycled (and established with fish) and I'm ready to add new fish, can I tank one of the filters off and use it on a 10g quarantine tank? I don't want to have a QT running all the time as I have nowhere good to put one. I'd like to just use it when necessary. If I put one of the filters from my established tank on a 10g, shouldn't the 10g be pretty much cycled immediately?

Also, would taking an entire filter away from the 20g tank make it's water parameters change for the worse?

After the quarantine, I would clean the quarantine filter, remove the bio material, and basically start it over on the established 20g tank.

It all sounds great to me, but I have no idea if it's a viable plan. Any help would be great!

Thanks!

[Betta man]

Quarantine is always a good idea. You won't have many diseases if you keep the water quality good and quarantine them. I have had issues with disease, so I'll be quarantining too. If you use a filter from your cycled 20 in a quarantine tank, it should cycle it quickly, but after it's in the quarantine tank, assume that it has disease on it and bleach it. If you don't stock your tank too much, it'll be fine with one filter. It sounds like it would work, but I'm no pro.

[Angelclown]

I would put two filters on the 20 gallon. Just in case the one you have on it decides to quit working.

[IAoddball]

I would personally use one sponge filter, and one power filter.

[emc7]

My question is this: In the future, once the tank is cycled (and established with fish) and I'm ready to add new fish, can I tank one of the filters off and use it on a 10g quarantine tank? I don't want to have a QT running all the time as I have nowhere good to put one. I'd like to just use it when necessary. If I put one of the filters from my established tank on a 10g, shouldn't the 10g be pretty much cycled immediately? Also, would taking an entire filter away from the 20g tank make it's water parameters change for the worse?

Yes, putting an established filter on a QT tank does make it cycled and good to go.

Taking a filter will affect the main tank. The bacteria multiply until there are enough to eat all the ammonia as the tank makes it. Take off one filter out of 2 and you take half the bacteria and suddenly the tank can process only half the ammonia. But this is no where near as bad as starting over. Filter bacteria can double their numbers in 1-3 days. So a "mini-cycle" is what happens. You skip every other feeding and do an extra water change and all will be well in a few days.

[jbliss145]

Thanks you all for the replies and the great advice. Since I have a smaller HOB filter I'm not using, I can just stick the filter media from that into one of my main filters for a few weeks to seed it. Then use that media and the small filter on the quarantine tank. That way I'm not taking away 50% of the main tanks BB by removing an entire filter.

I'm cycling the newly setup tank now. After doing a bunch of reading, I decided to try Tetra Safestart with a fish-in cycle. I added 6 small rasboras with a bottle of Safestart. I waited 48 hours before testing the water and have 0 ammonia, 0 nitrite, and 5 nitrate right now. (temp is 78 degrees, pH is 7.4) I'll be interested to see if this stuff really works. Those numbers look like a cycled tank, but I don't trust any readings after just 2 days. We'll see.

Thank you all again for the great advice!

[MainelyFish]

How long do you guys quarantine your fish for before you add them to your large tanks?

[jbliss145]

Originally Posted by MainelyFish How long do you guys quarantine your fish for before you add them to your large tanks?

I've heard people doing anywhere from a few days to several weeks. I didn't do it for the first 7 years of fish keeping and got very lucky. Then the worst happened and I lost ALL of my fish. I'll be using a quarantine tank from here on out. I'll probably leave them there for 3 to 4 weeks. But I'm no expert, that's for sure.

[emc7]

I hear numbers from 10 days to 8 weeks. I think 4-6 weeks is pretty normal. Some people use a tiered system of several stages such as a course of preventative meds or adding one of your existing fish to the Qt to see if it gets sick or makes the new fish sick.

I think it depends on the source. I'm not going to QT as long from a friend's fishroom as I would a freshly imported, wild caught fish (these are usually the ones you want to feed anit-parasite foods and maybe dip in anti-parasite meds). There are a few people whose QT system I trust to make fish safe for my tanks.

IMO store fish need QT most because you don't know their source and you have to assume they'be been exposed to disease from around the world in the wholesaler and LFS systems.