New 5 gallon nano tank

[mnccnm]

So, I assumed that placing a small (3" X 4") sponge filter in my fully established 125 gallon Oscar tank for 2-1/2 weeks, then placing it in my new 5 gallon tank would be enough to establish (seed) the 5 gallon tank. Well, guess what? It wasn't.
2 days after stocking the tank with some neons, guppies and a couple of dwarf gouramies both the amonia and the nitrites spiked, (.25 and.5 respectively). I did a 3/4 water change and added some prime, and scooped up a cup of gravel from the Oscar tank and placed it in the tank as well. Retested and no amonia or nitrites.
Tested today (day 3) (.25 and .5) Did another water change and again added prime, tested again, all good.
Is doing water changes daily going to slow the cycle? Is the Prime going to keep the fish alive if added daily until the cycle complete? Any other ideas on speeding the cycle up?

 

[Circus]

You could attach a piece of cycled filter media to your sponge filter, possibly using a rubber band.

 

[OliveFish05]

Hi! So I don’t know a whole lot about cycling/seeding/establishing tanks, I have only ever had two of my own, but I do see a few problems

Guppies are hard water fish, while Neons and gourami are softer water fish. Do you know the GH of your water?

Another problem, 5 gallons is not big enough for any of those fish, even if they were the only thing in the tank.

Now, speeding the cycle up. I would put some filter media from a more established tank over the sponge filter, like Circus suggested, whiling continuing to do daily water changes and doses of Prime.

If i were you though, I would take the fish back to the store you got them from, if possible. Really the best options for a 5 gallon tank would be a pea puffer or betta fish, or some shrimp and snails

 

[PheonixKingZ]

Is doing water changes daily going to slow the cycle? Is the Prime going to keep the fish alive if added daily until the cycle complete? Any other ideas on speeding the cycle up?

No, it will speed up the cycle.

It will detoxify ammonia, nitrite, and nitrate for 48 hours, so yes, it will keep your fish alive.

Move a slice of media from the 125, over to the 5g tank.

 

[Essjay]

after stocking the tank with some neons, guppies and a couple of dwarf gouramies

That is very overstocked for a 5 gallon tank, and the fish need larger than 5 gallons. The bioload of these fish in such a small tank will be too much for even a cycled filter; and the fish will be stressed in this sized tank.

Edit to add -
Requirements for these fish:

Paracheirodon innesi – Neon Tetra (Hyphessobrycon innesi, Cheirodon innesi) — Seriously Fish

www.seriouslyfish.com

Poecilia reticulata – Guppy (Lebistes poecilioides, Girardinus guppii ) — Seriously Fish

www.seriouslyfish.com

Trichogaster lalius (Dwarf Gourami) — Seriously Fish

www.seriouslyfish.com

 

[Cydeth]

This is not a recommendation of this particular product, but it is a recommendation of this type of product.

This is a small sponge filter with a pot below the sponge to add cycled biological media. If you can get one of these locally it would allow you take media from your larger tank and quickly add a nice portion to your smaller one. Even gravel would be usable in the small pot.

Of course, this will not solve the problem of over stocking.

https://www.amazon.co.uk/dp/B07R8XYFSR/?tag=