Beginner Help Please

It is important to keep nitrite down. Nitrite binds to the oxygen receptors in the fish's blood and stops oxygen binding. The blood turns brown and nitrite poisoning is sometimes referred to as brown blood disease. Basically, it does to fish what carbon monoxide does to us.

I’m not familiar with that product but the instructions on the bottle should be followed to avoid unnecessary wastage or pollution of the water.

Good news it is on the right track and we’re working towards a 0 reading.

What Littlefish is referring to is that when bottled bacteria products were first brought out they contained what they thought was the right species of nitrite eaters but we now know is the wrong species. Dr Tim Hovanec did research into this while working for Marineland and discovered which the right species was. Marineland and Tim Havonec copyrighted the use of this species. Marineland was taken over by Tetra who rebranded Marineland's product as Safe Start. Tim Hovanec left the company,and set up his own, which makes Dr Tim's One and Only (which is harder to get in the UK). For years only these two companies had the rights to use the correct species.
These two products Tetra Safe Start and Dr Tim's One & Only, are known to contain the correct species of both bacteria. It may be that other brands are also using the correct species now under some agreement, but we don't know which they are.


You may as well use all the Safe Start that you have to cycle the tank, but once cycled you don't need to use it unless you do something to kill the bacteria (some medications do this, and not dechlorinating the new water at a water change during the first year or so can also kill them)
The product instructions will tell you to use it routinely but then they want your money.

I can't find that filter by googling it. What is the name of the tank? Aqua One's website should have the manual, which will include the filter.

What is the media inside the filter? Sponge is just about the best medium for small filters, but many contain nothing but carbon cartridges.

I can't find that filter with a description anywhere - it's not on Aqua One's website and there's no manual there either.

If the service pack is all that is inside the filter, I agree with fcmf that removing the carbon and phosphate pads and replacing them with plain sponge would improve the filter so you wouldn't need to replace the whole thing.
Any brand of filter sponge will do as long as it can be cut to the exact size of the carbon and phosphate pads. If you could find a coarse sponge and a fine sponge and put the coarse sponge first in the direction of water flow to catch the big bits, then the fine sponge last in the direction of water flow to catch the small bits that went through the other sponges, that would be the best arrangement.

Prime is widely available all over the world.

It is useful during cycling, but since Seachem won't say what's in it I prefer not to use it in cycled tanks. There are other water conditioners which also detoxify ammonia, though only Prime claims to detoxify nitrite