Mistake made with new aquarium

Question
I made the mistake of setting my aquarium up and stocking it too soon.  The aquarium is a 30 gallon tank with an external filter, heater, and I've provided a large air stone with pump.  I added this product by TETRA that states you can add fish as soon as product is added. It's a new product. It states on back that it contains bacteria essential to fish.  I've read many comments about the product not working, now I'm worried about the fish I've purchased.  I have one molly, 2 platys, 6 danios, and three other fish that are livebearing fish. I'm not sure what these fish are called.  My ph is 7.0 and my temp is 75 degrees.  I stocked the aquarium 24 hours after setting it up.  I'm worried now about the cycling process and if my fish will live. What can I do to keep them alive?  Today is day 3 and the fish seem fine.

Answer
Hi Joseph

Many people make the same mistake you did. I had one tell me she put 50 guppies in a 20 gallon tank the same day she set the tank up and couldn't figure out why all but 4 of them died.

Luckily for you, New Tank Syndrome occurs less in larger tanks. However, the cycling process still needs to be performed the correct way. Adding bacteria additives is the most incorrect way I can think of. These are short cuts that I would never use nor recommend. And as you said, most of them don't work.

This is what I suggest you do...

Make sure your power filter is the correct size for your tank. In my larger tanks, 30-55 gallons, I use 2 power filters on both sides. In my 55 & 75 gallon tanks, I use 3...2 large ones on both sides and a smaller one in the middle.

Do about a 75% water change vacuuming the gravel thoroughly. Make sure you get all areas of the gravel. Use a 5 gallon bucket to add the new water to the tank. Make sure the water is the same temperature by touch as your existing water. And remember to add water conditioner to the water BEFORE you add it to the tank, and I would recommend using Stress Coat or AquaSafe. Do NOT use Amquel+ as it removes oxygen from the water. Replace your carbon filter cartridge in your filter. And given the fact that your tank is new and the amount of fish you have in it, I would recommend adding a 2nd power filter to the other side of your tank. I also recommend replacing the carbon filter cartridge every 2 weeks.

Every few days for the next 2 weeks, do a 15% water change and keep an eye on your levels. Check your ammonia/nitrite/nitrate levels as well as your pH. 6.0 - 7.5 is good for the fish you have. If the ammonia, nitrate and nitrite levels are high, do another water change until they are in an acceptable range. Keep the temp between 72 and 78. After that, do a 15-20% water change weekly, keeping an eye on your levels. And in case I didn't make this clear.....no more bacteria additives!!!!!!!! no no no

Your tank is large enough that your current fish should be ok. The fish you have a very hardy fish that can accept a wide range of water conditions. Until your tank is cycled in 4-6 weeks, I would feed the fish sparingly to avoid excess food fouling the water.

Hope this helps you and if I can be of further assistance, please let me know.

Richard