Nitrate Levels, What To Do, If Anything?

[Schmill]

Test Kit: API Master Test Kit

Well my fishless cycle completed about a week ago so at the weekend I did a large water change (80% ish) and then put in my new fish.
However today (2 / 3 days later) I have done my water tests, and although the ammonia and nitrIte levels are sitting nicely at the minimum reading on the test kits, the NitrAte level is up at 40 ppm. (This is TOTAL NitrAtes according to the test kit, not sure if this is different to other kits).
I've read that really I don't want it to go much above 40ppm, but have a few questions before I go and do another large water change just 3 days after the last one!

I have live plants in the tank, and so for them have JBL 7 Clay balls burried in the gravel which is supposed to help the plants, but they seem to claim they contain no nitrAtes.
Also my tap water is measuring at something between 15 and 20 ppm for NitrAtes, so I'm not even sure that changing the water with tap water will help for long?

So, my first question, should I do a water change? If so, how much should I do?
Also should I use my tap water, or should I use some Ro Water that I can get from a friend? Presumably the Ro water has a NitrAte level of 0ppm, but I'm not sure what other affects this might have on the tank.

Thanks in advance!

 

[waterdrop]

Schmill,

You've asked several questions, each of which is the type of thing that may draw long answers and take a bit of time, at least from my reading here.

Let me just give a short response to get one of them started. I believe it is important to understand that Nitrates being at 40 is not the same type of concern at all as having ammonia or nitrite in the water. While those two toxins present immediate concern for your fish and call for immediate action, Nitrates do not present the same kind of threat. If you search extensively here you will find threads that document various effects of Nitrates starting only at much higher levels, like 400 and 1000. Still, you will also find plenty of agreement that 40 is a good recommendation for an upper number to work towards and a sign of a healthier tank that is receiving an appropriate level of water changes.

I think for you the practical take-home message of that is that getting a 40 reading on the api test doesn't mean you should feel you have to perform a water change right away, it just means you need to be figuring out a change pattern - just as you are doing. Since you have the problem of higher Nitrate levels in your source water already, you might want to consider smaller but more frequent water changes. My first take is that RO water is too radical a move for the problem you describe. I'd of course hear what others recommend, but RO water of course means more significant investment either of time or money or both and is more complicated to learn. Minerals and other things would need to be added back that water and testing for that would be needed. Its certainly possible to learn about here and do, but I would be sure to investigate first whether it is even the right thing or whether there is a simpler approach.

Many of the UK members have to deal with higher Nitrate source levels and I'm sure they've worked out guidelines for thinking about this. Also, you may have things going on with your special plant ferts. and that may need some time to sort out - either for you to discover more info here about the JBL or more time to see if there is a spike in what they give off, if anything.

~~waterdrop~~

 

[emmag21]

80% water change?

 

[Miss Wiggle]

80% water change?

at the end of a fishless cycle you do a massive water change to get rid of the nitrates which have built up. i actually recommend a 90% change but 80 is fine.

it's fine to do big water changes though, the bacteria are all in the filter and adding new water won't kill them off. if i spot a problem in the tank i do a 50/75% change with fish in immediatley. just need to run water back in slowly to catch back up to temp.

regarding nitrate, as waterdrop said the two main things to remember are that you're unlikley to see any fish health problems caused by nitrate unless you get up to 100ppm or more, and that also the nitrate test kits are not accurate so give an indicative reading only, not a factually correct reading.

that being said, in a sensibly stocked and maintained tank your nitrate should rise by 20ppm in a week (so from immediatley after a water change to immediatley before water change there should be approx 20ppm difference). So if your tap water has 20ppm then that's your baseline, by the end of the week you can expect this to rise to 40ppm. If you are getting a rise of more than this in a week then it can be a sign that the tank is overstocked, the filter is underperforming or the tank is being over fed. Can you let us know what size your tank is, exactly what fish you have (and how many of each species) and what make/model of filter you are running?

 

[Schmill]

Can you let us know what size your tank is, exactly what fish you have (and how many of each species) and what make/model of filter you are running?

Tank is a 60L tank, which when allowing for gravel, ornaments etc takes about 50L of water.
I am running an Interpet PF2 in-tank pump / filter, (currently with the flow rate lowered so as not to blast the fish around-and-around the tank!) Interpet PF2
I also have a 6" airstone laid across the back of the tank as part of one of the ornaments and this runs whenever the light in the tank is on, (at the moment 9am to 9pm)
The only fish I have are the ones I put in on the 10th May, and are as follows:

1x Bulldog Pleco
2x Male Guppy
4x Female Guppy
4x Rainbow Praecox (Neon Rainbow) (2 males, 2 females)
2x Albino Corydoras

1x as yet unidentified fry! (was in the bag with the female guppies, so either one of them gave birth whilst in transit, or else the fry was netted out of the tank at the LFS and no-one noticed!)

I guess I'll just give it a while and keep monitoring the nitrate level.

 

[rabbut]

The pleco will be kicking out a lot of waste into a tank that is quite heavily stocked. This isprobibly the issue You may find that you need to do twice weekly 30% or weekly 50% waterchanges to keep on top of the nitrate build-up. Nitrate is not a major concern unless you have very soft water, in which case it's acidicness risks a pH crash. In a well maintained tank, the chemical isn't too bad, in fact many plant growers intentionaly add it

If you don't like the look of that waterchange regeme, remove the pleco and I bet the issue will go away Also, how much are you feeding and how often? If the stocking isn't the issue, it will have to be overfeeding. Are you the only person whom feeds the fish?

All the best
Rabbut

EDIT TO ADD: the corries need to be in groups of 6+, and are possibly a little too large for a 60l. Albinos are a large corry, reaching 4inches when adult. See if your lfs will swap or part-ex them for a group of pygmy corries