NITRATE

Hi there,

setting up a small quarantine aquarium, next to my main one and today measured the water...
ammonia 0
nitrite 0
nitrate 20-80 very hard to see the exact figure on API kit

anyone can tell me the ammounts tolerated by plecs, cardinals, red cherry shrimp or pearl gouramis?
I have a que waiting

Being honest about it mine are rarely over 10 ppm .I know that they are not as bad for fish but in any tank with a weekly water change they should stay around 10 in my experience.Yours being on the high side of 20!! 30 being bad i would do a water change.But seen as this is a new tank by the sounds of it those levels should come down espically when you do the next water chage.How long is the tank cycled ?

20 should be considered the very maximum for most fish. You should be aiming for 10 or even less. Increased water changes for a couple of weeks should bring it down, sounds like tank is not fully cycled.

the tank is arround 3 weeks now. I actually dropped sponge from the main tank and swirled a bit in the small tank.
I think that speeded it up a bit.
will change some whater tomorrow and see the readings.

as soon as it's below 10, it's ready right?

I would do a change and test a few days later to see where you are then.
The last thing in my experience to go down is NO3.
Seen as you have no reading for ammonia or NO2 i dont think you tank is far off being cycled now.
Do you have any fish in the tank now ?

No fish in it at the moment, but I'm treating my main tank with API MELAFIX and it costs a fortune (cardinal tetras have fin, mouths with lumps and one cardinal with poped eye), so I was thinking to place 10 cardinals in it for a week or so till they get better. it's only arround 20 litre tank, so treating it will be way cheaper than RIO400

PS by the looks of small tank looks a bit dirty as I squeezed a bit of old main tank spunge in to it.. so I'll change some water or suck some of dirt out of there too?

also was thinking to replace 100% of small tanks water with main tanks water, sinse it has medication in it and I will use to medicate the same fish that are in the main tank..

It is not possible to tell the state of how far a tank has ‘cycled’ from a single set of readings: you’d need to have a series of readings over a period of several weeks to see where we see increases/decreases in ammonia, nitrite and nitrate.
To be honest it can take 6 months and more for a tank to be fully mature.

The Nitrate will simply keep on increasing unless it is removed by having an in-tank biological anaerobic denitrification (or the anaerobic oxidation of ammonia with nitrites) system running, or you do plenty of regular water changes, or you have plenty of healthy plant growth, or you use a specific nitrate removing filter material.

The levels of nitrate tolerated by freshwater fish varies quite considerably…..but the levels you quote for the species quoted is too high.

Regular Partial water changes are the best solution, but in an emergency case I would recommend using something like JBL NitrEx resin.
What you do, however, need to be careful of in having zero nitrates (and resins can easily produce zero nitrate) is that if the tank is not balanced then you be increasing the chance of favouring the use of sulphur by sulphur-reducing bacteria to produce hydrogen sulphide (a lot more toxic than nitrates).

As you have a quarantine tank, then I presume that you’ll be using medication….if that medication contains methylene blue (melafix doesn’t as it is aromatherapy for fish really) then methylene blue will also protect the fish somewhat against nitrate poisoning.

Ian