Nitrates

Good evening Professor,

This may come across as a trivial question, but please bare with me as I outline the reasoning behind the question:

A 10-15% water change is recommended on a weekly basis to help control nitrates. In some instances, based on the bio-load of the tank, it could be recommended to do a higher percentage, or a more frequent water change.

I do my waterchanges on a Sunday afternoon, usually. I think you will agree with me that sometimes certain weekends our activities run away with us, and we land up missing the water change... and only get to it the next weekend. Thus I've been through a 2 week cycle between waterchanges.

I generally like to keep a check on my nitrates, and it's a given that there is obviously a lot more nitrates in the water after 2 weeks than the 1 weeks cycle.

Is this "fluctuating" in nitrates a dangerous thing?

I know high nitrates is considered very bad, and I realise that the optimum would be to always have as low a level of nitrates as possible. With pH we have all agreed that having a constant pH is more important than having a perfect pH. Would keeping Nitrates at a constant (for eg below 20ppm) be the same principle?

 

Hi Zoom,

Firstly let me congratulate you on becoming one of the mods of the forum. May you not have to wrap me over the knuckles for transgressions......

This is a complex question requiring a complex answer.

Firstly, the fishes that you keep decides how sensitive they will be to nitrates. Barbers and carp can cope with 100 ppm (mg/litre), goldfish and Malawis with 50 ppm, tough tropicals in general with 20-30 ppm and then the sensitive fishes, discus and altum angels, 10 ppm or less.

If your levels are higher than the recommended levels for these fishes the fishes will not grow quickly, will become permanently stunted in their growth, will be more prone to disease, will not spawn properly and suffer from infertility and will only live for a shorter period. Too high nitrate has a bad effect on just about all processes in the body because the idea is that it causes acidification inside the cells of the fish and the fish continuously uses a huge amount of energy to compensate for this whereby just about every process in its body is negatively influenced.

As a result of this, nitrate levels and their management to low enough levels is something that is to be taken very seriously and if you slack out by having a lekker braai over the weekend and not doing the water change your fish will pay the price.

What is also very important is that if you do a 15% water change and you do the calculation as to how much you dilute the nitrate you are actually achieving only a very small reduction. You need to do larger percentage changes to actually reduce nitrates significantly and to keep them low enough for the fishes to thrive. In discus keeping you need a 50% water change once a week invariably. Fluctuations are not the problem, the absolute levels are what are important and if you have one week of 20 ppm nitrate instead of 10 ppm your fishes will feel it, make no mistake. For fishes that are less sensitive to nitrate what this means is that you can change 50% of the water every 2 weeks, but watch the upper limit of the nitrate by using an accurate test kit. Also, if your fish load is lower then you can get away with less water changes.

I hope this answers your questions, but I can categorically state that high nitrate levels are most probably the biggest cause of problems with fish health and growth in fishkeeping.

Oh, you asked me to "please bare with me" but as I have indicated before this means, "please kaalgat with me". I am sure you wanted to write "please bear with me". The wonders of the English language....

Kind regards,

Dirk

 

very very funny:bigsmile: Prof- LOL

Very good question Zoom.
Never underestimate the power of Nitrate

 

Yip to me

 

OK,

But let us forget about the professor and his grappies. I think the point that Zoom has raised here about the nitrates is very important and is the single most important factor that aquarists tend to forget, yet it leads to tremendous problems in our fishkeeping.

Kind regards,

Dirk

 

You wanna know what even funnier? I originally wrote "please bear with me." Posted it, and then edited it to say "bare" because you had this same dig at someone else on the forum recently about it...

LOL

Ok... well that answers my original question. I skipped the W/C this weekend due to a very busy schedule. So then instead of "Tasaing" after work, as my wife calls it, I should then do the W/C as soon as I ge the chance during the week. So tonight... Zoom will be doing a water change!