Adding new fish w/o quarantine

[Charlie]

Hello,

I have a 20 gallon long tank that is fully cycled. I gravel vac and do ~20% water changes weekly. I don't have space for a quarantine tank.

I added 5 new guppies 2 weeks ago and this week 2 new guppies and one of my original guppies died, all within a few days of each other. 

My question is: should I treat my tank with the 3 recommended meds from aquarium co-op everytime I add new fish to my tank?

[Pookies Aquatics]

First, what type of fish do you have in that tank? Also, have you noticed anything wrong with the fish, for example worms, loss of appetite, etc. You could add the 3 meds, but it will be better if you can identify exactly what disease it could have brought in and then treat for that. 

[Charlie]

Right now, I have 3 fancy tail guppies, a clown pleco and a mystery snail.  My ammonia and nitrites are 0 and nitrates hasn't gone above 20 ppm. 

I didn't notice anything wrong with the new guppies. They were active and eating. The older guppy was the only one in the tank that was lethargic and wasn't eating as much. It doesn't look like any of them have ick. 

I have noticed detritus worms floating around and some tiny, white squiggly things on the inner glass. I wipe the inner glass with a paper towel during my water changes to clean up as many squigglies as possible. 

The remaining fish and snail all look fine and are active. I plan on adding more guppies but I'm going to wait a few more weeks to see if anything else dies. 

If I treat my tank now and then again when I add new fish, will the meds have a negative effect on the fish that were already treated? 

Thanks.

[KBOzzie59]

"My question is: should I treat my tank with the 3 recommended meds from aquarium co-op everytime I add new fish to my tank?"

My first thought is no.  How often do you add new fish?  Not even room for a 5.5 or 10 gallon tank? I think most meds  are dosed for every 10 gallons.  With a 10 gallon you would use half the meds you are now using and if you went with 5'ish gallons it woould be 1/4 of what you are now using.  Plus it's safer for you fish.

Don't have to leave it setup full time.  Does not even need to be a tank @Irene recently did a video about her setup.

 

 

[Pookies Aquatics]

For best results, just do a quarantine tank, but since you can't, I would recommend adding the meds every time. 

The quarantine tank doesn't need to be a full tank. I just use a plastic storage bin, which I keep under the tank with a light.