cowgirluntamed said:
Wow...I don't know if I would do them all together but 2 groups sounds good! I take it then 15 neon tetras and 1 bristlenose later would be just fine to keep in there permanently with the floating plants? I do love the water sprite. I like it alot me than wisteria!(tried that in my 5 as they didn't have water sprite. Due too a higher light intensity and too many root tabs I had a bad case of hair algae that killed it. Still have algea even with less light time...oh well.)
If you do split the new fish, it is a good idea to wait a few weeks between if possible. Never add new fish to a QT that is still holding new fish previously acquired. This is a very good way to initiate some issue like ich. Once you have new fish in the QT, leave them there on their own for 4+ weeks [more on this below]. Move them to the display tank, and keep a watch out for signs of problems, which might cause them to need returning to the QT. Less likely to be disease, as anything they might be carrying that only appears when introduced to the display tank will likely be in the display tank now. But sometimes there might be issues more along the line of temperament/aggression. Though with tetras and rasboras, not very likely I grant you.
I would say four weeks is absolute minimum, and longer may be advisable depending upon the species and the source. There are several aspects to this. The obvious one is disease, and here I hold "common" fish that are commercially raised in QT much longer than I would wild caught, or those from certain known sources. There seems to be a lot of internal protozoan and pathogens in commercially-raised fish, and I suspect this is either occurring at source (the hatchery) or in the stores, chain stores like Petsmart being especially bad for this due to their procedures/maintenance. Dealing with an independent store, and one that uses their own suppliers or direct from the habitats, is much safer right off the top. I have had three very serious issues over the past five years, and all three came in with "bread and butter" fish from chain stores; I will no longer even enter the fish area of these places. Only once in 20+ years have I had disease enter with wild caught fish, and that was a case of gill flukes on some corys.
The other aspect of the period in QT involves the fish itself, aside from disease. It is much easier to get fish feeding in a QT that is smaller and where they are alone (even if mixed species at the time), because you can add more food and not worry much about over-polluting the tank, as it is easy to water change and vacuum the substrate more often if you need to. Some fish, and here wild caught are particularly affected, can be difficult to get eating well, and this is only prolonged or perhaps completely unsuccessful if the fish is in a larger tank where it feels threatened by other fish species.
After the new fish are moved out of the QT, I always do a few 100% water changesin the QT using tap water without any conditioner. I simply drain the tank down to the substrate, refill, then repeat in a couple days. The chlorine in the tap water will kill some pathogens obviously, which is the whole idea, but it will not remove all of the nitrifying bacteria unless the level of chlorine is very high, and even then it is doubtful. The plants and snails will be fine. The sponge filter (sponge filters are excellent in a QT as they are effective filtration but easy to maintain) I rinse well under the tap. After I have moved new fish into the display, and the QT remains fishless, I continue the normal 50% water changes every week when I do the other tanks, but I never use dechlorinator in the QT unless there are fish present.
A group of 15 neon tetra and 1 bristlenose will be fine permanently in a 20g. Keep the temperature around 75-76F. Neons are not warm water fish, warm meaning above 76-77F, and they will be healthier at lower temperatures, from 70-76F. The Bristlenose, if one of the common species of
Ancistrus and not wild caught, will be fine with this. They tend to remain at the 3-4 inch length, though some species can reach 5 inches which to me is pushing it in a 20g.
Byron.