Ei And High Nitrate Levels

[CletePurcel]

I have been dosing with EI using the basic macro and micro solutions from James' Planted Tanks page. The macro solution (Potassium Nitrate and Potassium Phosphate) I add 6ml every other day except Saturday which I believe works out at 3ppm per day or 18ppm per week (I have about 80 litres of water).

My tap water already contains 30ppm nitrates. I am having very high Nitrate reading at the end of each week (80ppm+). Before I started EI I was getting readings around 10ppm. I believe the objective is to aim for 20-30ppm nitrates. I do a 50% water change each week to reset the system.

I am thinking that I should reduce the Potassium Nitrate in the macro solution as it is not needed. Is this correct? Could the tap water in addition to the macro solution explain the high nitrate readings? Or could it be something else?

My ammonia and nitrite are always zero. I am using easycarbo (1.5ml per day) and have just above 2 wpg lighting. The tank is about 50% planted. I also have a slight green algae problem developing.

Any thoughts?

 

[angelfishguy]

Alot of people with planted tanks dont test for nitrate because they are effectivly dosing it.

 

[CletePurcel]

Alot of people with planted tanks dont test for nitrate because they are effectivly dosing it.

I understand that. I am trying to get a feel for how the system works so I am still testing. It just seems to me that nitrates at 80ppm+ seems a tad high.

 

[angelfishguy]

Theres members on here that will say nitrates at 200ppm are fine with no ill effect to the fish. Im not the best at dosing ferts and amounts but id wait for a more experienced member to comment before dosing less

 

[CletePurcel]

Anyone?

 

[aaronnorth]

To be honest some people would say 30ppm NO3 is getting close to high, they believe 40ppm is harmful.


Is the 30ppm NO3 in your tap water what you have tested, or a water report from your supplier?
Because if your test kit is wrong (and the chances are quite high that it is) then the 80ppm will also be wrong.

You said you have 30ppm in the tap water, but then it decreased to 10ppm at the end of the week. This means the plants were using 20ppm of NO3 (plus whatever the fish produced).

What doesn't make sense is that from your readings after EI, you start with 30ppm and it rises to 80ppm;
we can make a fairly accurate assumption the plants continue to use the same amount of NO3 as before, and the fish continue to produce the same amount of NO3 before, (so it should read 10ppm) - so how can you possibly gain 70ppm from dosing 18ppm of NO3 in the EI solution every week?

surely it should stick at around 30ppm?

Thanks, Aaron

 

[CletePurcel]

To be honest some people would say 30ppm NO3 is getting close to high, they believe 40ppm is harmful.


Is the 30ppm NO3 in your tap water what you have tested, or a water report from your supplier?
Because if your test kit is wrong (and the chances are quite high that it is) then the 80ppm will also be wrong.

You said you have 30ppm in the tap water, but then it decreased to 10ppm at the end of the week. This means the plants were using 20ppm of NO3 (plus whatever the fish produced).

What doesn't make sense is that from your readings after EI, you start with 30ppm and it rises to 80ppm;
we can make a fairly accurate assumption the plants continue to use the same amount of NO3 as before, and the fish continue to produce the same amount of NO3 before, (so it should read 10ppm) - so how can you possibly gain 70ppm from dosing 18ppm of NO3 in the EI solution every week?

surely it should stick at around 30ppm?

Thanks, Aaron

I have more fish now than when I started. So I think that the combination of NO3 from the fish/food and the tap water pushes it up and there is no need to dose extra NO3.

The NO3 from the tap is 30-40ppm (the water company says 25). Although it is hard to read the test. The 80ppm+ might not be accurate either (but it is definitely higher than it was before).

I just received a message from Tom Barr who said if my NO3 is 30ppm out of the tap to just substitute K2SO4 for KNO3 at my level of planting.

 

[JoshuaA]

Yeh do that and throw your nitrate test kit out

Can't stand mine, so innacurate... I can do two tests at the same time and they come out different shades. Almost anything effects it... in fact if there is a tiny amount of nitrite... TINY amount the Nitrate goes off the scale on my API test kit ( Don't worry it was a fish-less cycle which had only just started reducing ammonia.)

 

[CletePurcel]

Yeh do that and throw your nitrate test kit out

Can't stand mine, so innacurate... I can do two tests at the same time and they come out different shades. Almost anything effects it... in fact if there is a tiny amount of nitrite... TINY amount the Nitrate goes off the scale on my API test kit ( Don't worry it was a fish-less cycle which had only just started reducing ammonia.)

Are any of the nitrate tests any good?

 

[JoshuaA]

None that I know of, the problem with the API kit is the second bottle is a mix of 2 solutions which unless shaken vigorously you won't get them mixed enough to get a good reading. Some other brands use 3 separate bottles for nitrate kit but in my experience have been just as unreliable.

I checked the water board for the estimated Nitrate in the water supply and then just ensure that I do water changes at least every week.