I have been having one sometimes two fish dead in the morning laying on the bottom. some have been lemon tetras, some blue tetras. no signs of anything. my water is fine.. nitrates of less than 10-15ppm, no ammonia, no nitrites. my ph when co2 is going is 6.4 and at night is 6.8 to 7.0. I just bought some aquari-sol and put some in the tank and raised the temp to 83 deg. F I don't know what else to do. I don't want to lose my fish! help?

First thing that comes to mind is something CO2 related. How are you controlling CO2 levels? A timer? Are your fish near the surface in the morning or acting otherwise stressed? How frequently is this happening?

Are you turning off your Co2 and running an airstone at night?

Are any of the fish acting in any way different that you can tell? Any torn fins, spots, red gills, scratching up against things (called "flashing")?

nope.. they aren't hanging out at the top.. most of the time they are staying out of sight among the plants. but that is common for the blue tetras. they are out at night going crazy.. I have lunar lights so I can see them. I have my co2 on about 2 bubbles per second and my drop checker is staying green. I have 1.5ml of 4dkh solution and 2 drops of reagen solution in the checker. any other suggestions?

Flashing and scratching are not the same lauralee...flashing would just be flashing intense colors maybe at a mate and scratching is...well scratching

at least thats what I understand...

I'd drop an airstone in at night and see if it continues. If you're using a timer, simply set the airstone to come off after your CO2 goes off...

How often are you losing fish?

There's 2 uses for the word, since the movement they make when scratching also tends to reflect light and "flash"

Torpedo- how long since you introduced any new fish into the tank? Do you QT all new fish?

What temperature were you keeping the tank before you started treating with AquariSol?

Yeah, disease was on my mind too. But what about the temporal pattern thats showing up? That's why I wanted to know fish loss frequency, to see if it's a coincidence or recurring theme...

usually 1 to 2 fish a day.. I do have an air stone that goes at night.. it comes on after the lights go out and my lunar lights come on. I don't qt my fish prior.. but I always buy my fish from the same lfs and never had a problem before. this sucks.

oh.. and I was keeping the tank at 76deg. prior to adding meds. read somewhere that the cooler water was better for the plants.

I have the same problem too...I have been losing my Otos that I purchased last week and I lost 1 of by bloodfin tetras. The other fish (even the neons) are doing fine and my water params are normal. My guess is that buying from Petco is not ideal but there is no reputable LFS within a 100 miles of here.

yeah.. that stinks when you have really no options of where to buy fish. I am fortunate that we have a few different lfs to buy from

You need to always, always, always QT new fish. Minimum 2 weeks, IMO.

Otos and tetras are examples of fish that are almost always wild-caught; which means that they could be carrying all kinds of parasites/disease and have undergone all kinds of stress between capture and your tank that stress them to the point that the parasites/diseases start getting the upper hand.

My guess is that you both introduced some disease into your tank.

I personally prefer to medicate with aquarium (or other non-iodized) salt, 1/2 tsp per gallon for 1 to 2 weeks. I like salt b/c it's typically less stressful on fish and fairly effective across a wide spectrum of health issues. I wouldn't mix this with a commercial med though?

ok.. I will have to remember to do this from now on. I only have a 5 gallon tank I can use for a qt tank though. I hope this medicine works! if not.. after a week of using I see no change.. I will use the salt like you said. thank you!

In general it's recommended not to dose with salt in a planted tank. If you are careful you can do it, but depending on your plants, you may have some melting.