# Nitrates after water change!



## Amaralluis (Oct 21, 2005)

Hi,

I just finished doing my weekly water change and added my regular fert dose.
3/4tsp kno3, 1/4tsp k2so4 and two pinches of kh2po4.

I tested for nitrates and it is betwen 0-10ppm but definately not anywhere near 10ppm.

Isnt this a little low? Shouldnt I be targetting 20ppm?

This could explain why algae is still growing?


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## MrSanders (Mar 5, 2006)

It would be of much help if you were able to share more about your setup, tank size, doseing routine etc..... Its hard for anyone to help you with out any information to go on


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## BryceM (Nov 6, 2005)

MrSanders is right. People will need a lot more info to help you.

In general, 10 ppm of NO3 is fine, less is asking for trouble if you have a high-light setup. A lot of people aim for 20 ppm NO3 to decrease the chance of running low.

BTW, how do you know your concentration is 10 ppm? Test kits can be horribly unreliable, and even top-end ones like Lamotte are best verified against a known solution. If you add X tsp of KNO3 to X gallons of water your concentration is at least what the math tells you, regardless of what your test kit says. It would be a big mistake to keep adding until your test kit registers it.

Without more info I'd guess your algae problems come from a lack of CO2.


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## Amaralluis (Oct 21, 2005)

Hi,

I guess you haven't read my other thread : http://www.aquaticplantcentral.com/forumapc/science-of-fertilizing/15175-what-else-can-i-do.html

It has all the info about my tank.

As for knowing what the concentration is, I use the hagen test kit and based on the color it tells me that it is much less than 10ppm.
Exactly how much I dont know, but I would say it is in the low side.
Should I increase the dosage to 1tsp instead of 3/4tsp?

I am not touching co2 anymore. Ph sits at 7.0-7.1 and kh at 170-180.

Trying to decrease ph creates problems for my bamboo shrimps (believe me I've lost a few and only now I realized that it was fro trying to achive a 6.8 ph).


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## JC1 (Jan 27, 2006)

Before you do anything else, I would strongly recommend calibrating the NO3 test kit. Mix a 10 ppm NO3 solution and test it. That way you will know the color of 10 ppm.

I'm no expert, but I do know every time I let NO3 get less than 10 ppm, I get BBA and green spot algae. I like to maintain between 15 and 20 ppm. And, if I let CO2 get to low, ditto. I read your other thread, and based on the pH change over night, you only have about 16 ppm of CO2. SLOWLY increasing to get about 30 ppm might help you. Slow changes would allow the shrimp to adjust. Besides, everything I can find on line says the Ninja Shrimp are pH tolerant, with a preference between 6.6 and 6.8, so increasing the CO2 would actually reduce pH into the optimal band for the shrimp.

HTH
Jim


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## MrSanders (Mar 5, 2006)

Well Amaralluis, I hate to be the one to bring it up but how are people supposed to know that all your info is in another post if you dont tell us.... to be honest we arnt going to go searching around digging up information about you to try to help you with your tank, it is BEST to put it all out where it is easy to go over in one post with the problems/questions you are having so other members can more easily help you.

First of all my advice to you is to stop going by what those test kits are telling you. They are cheap hobby grade kits, and not accurate by any means nor are they telling you much as to what is actually in your water. your tank is a 75 gallon, with 140 watts of lighting..... 3/4 t. KNO3 3/x a week is MORE than enough nitrate for this tank...... and its safe to say that you by no means have a lack of nitrate. 

I think your biggest issues are A.) lack of CO2, if your rested tank sample test 7.6, you need to get your PH down to 6.6 or a bit lower within the first hour of your lights being on from CO2 injection. low CO2 levels and unstable levels are always going to cause algae problems.... I know this from expierence it has happened to me over and over.... since swiching the the mist method I no longer have problems keeping CO2 consistant..... and believe it or not I drop my PH to 5.6 by the time my gas shuts off at night...... the fish are just fine.... you can get more CO2 in there and I really think it is going to help things GREATLY just do it slowly and be around to keep an eye on the fish.

Next I am wondering about your traces..... in your other post it said you are using 60ml of nutrafin plant gro iron 3x a week...... I dont know whats in this product.... and if it is a balanced trace mix.... but you should not need to dose anything near that amount. I would use Flourish, TMG or CSM+B, all you need is around 15ml 3x/week... NPK all look good, handle traces.... and work on getting the CO2 up.... if your not willing to add more CO2, then i would get used to having the algae


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## Amaralluis (Oct 21, 2005)

Co2 is out of the question for me at this time.

I have 7 bamboo/rock shrimp left out of 12 before I realized that it was the decrease of co2 that was wipping them. They just dont seem to like anything lower than 7.0. And lets not forget losing my most awesome shrimp I've had, ninja shrimp. All because of trying to push c02 too much.
There's gott be another way for me to battle algae without sacrificing anymore animals.

That is what I am hoping to find. I hope you understand.


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## hoppycalif (Apr 7, 2005)

What people are trying to say is that CO2 is not likely to be what killed your shrimp, but excessive nitrates possibly might be. We add nitrates to our tanks when we have fast growing plants that are using up what's in the water. But, fast growing plants come from high light intensities - more than 2 watts per gallon, with good reflectors - and sufficient, steady CO2 (30 ppm or so throughout the lights on period.) So, if you don't have fast growing plants it is possible to build up too much nitrates in the water. And, the test kits available to us at reasonable price and availability are not accurate enough to use to test for nitrates. So, we calculate how much nitrate it takes for our tank, and for yours, 3/4 tsp three times a week is highly likely to be too much.


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## Amaralluis (Oct 21, 2005)

Thanks for the help.

The Fertilator says that I am only adding 9.57ppm of nitrates, which the test kinda confirms to some extent.
Fertilator sugests a concentration of 10-20ppm, and right now with 3/4tsp it's below the fertilator sugestion.

I also have a hard time believing that the test kit is so far off. Obviously it is not providing with the accurate amount but I dont think that it tells me a 5ppm solution when in fact it is more like 50ppm.


What frustates me is all this contradicting info.
You and others are saying that co2 levels are low, I've seen charts and chuck's calculator say it is good.

Same for Kno3, one side says I am dosing too much, on the other not enough (fertilator) and so on.

I just dont want to lose anymore animals with my experimentation.


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## MrSanders (Mar 5, 2006)

If your doseing 3/4 t. KNO3 3x a week to a 75 gallon tank your not adding 9.57 ppm a week. That number is per dose, depending on what you figured you actual water volume is. Per week you are closer to 30 ppm nitrate.... which is more than you need by a long shot, I would imange your tank would probably use maybe 10 ppm a week with that amount of light.... and I highly doubt nitrate or CO2 is what killed your shrimp..... ever check ammonia? that will kill shrimp in the blink of an eye, how about heavy metals? or water changes with out adding declor? 

It really doesnt matter to any of us if your not willing to try to get more CO2 into your tank, but as many have said it is most probably the biggest cause of your problems..... and charts dont apply to most of us.... look through the forums, there arnt many that the PH, KH, CO2 relationship actually works for..... for some reason it just isnt accurate in measuring CO2 in a lot of our water sources.


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## Amaralluis (Oct 21, 2005)

I did check for amonia last saturday when another of my shrimp died.
It was clear as water, meaning zero. 

I dont know about heavy metals, I have water well and the last test that was done, wasnt too bad.

I've noticed that the shrimp deaths happened towards the end of the week, could it be due to the high level of nitrates?
Is there a correlation between the amount of nitrates and co2?

I am going to reduce to 1/2tsp kno3 for now, and test the water to make sure that it stays at around 10ppm.

I want to clear nitrates as being the cause of shrimp death.

For now I am not touching co2.


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## BryceM (Nov 6, 2005)

High nitrates can absolutely kill shrimp, and about anything else if they get high enough.

Maybe you'll benefit from my experience. I started out my recent tank with DIY CO2 and EI dosing methods. I have a relatively heavy fish load and I started experiencing some algae issues in my tank. No surprise there. I kept increasing my nitrates & phosphates, thinking that my problems were coming from a nutrient deficiency. I finally gave up with DIY CO2 and went to pressurized. This improved my BBA issues, but I started to notice green dust algae covering everything. I increased my nitrates & phosphates again to about 30 ppm per week, with tank readings of about 10-20 ppm of NO3 by my hobby-grade test kits. I was becoming horribly frustrated since I was actually starting to loose some nice plants due to the green dust.

I then bought a Lamotte PO4 and NO3 kit. My nitrates read above 80ppm. I did a couple of successive water changes, got it to about 20 ppm and my fish all looked much healthier. They started showing spawning behavior almost immediately. I attribute my high readings to doing less than 50% WC's and overdosing my nitrates, in combination with relatively high feeding. The green dust vanished in about 3 days.

Bottom line: incorrect information from hobby-grade test kits is MUCH worse than no information at all. If I'd just watched my fish and plants I'd have probably made smarter decisions.

Shrimp also don't live forever and a few deaths now and then are to be expected.

There is no meaningful correlation between NO3 and CO2.

The experience of hundreds of people that post on this site is that insufficient CO2 is the most important cause of algae issues. Shrimp can certainly be more sensitive to high CO2 and low pH than fish, but it really doesn't sound like you are even close to high CO2 levels. Of course, you are probably relying on cheap pH and KH test kits too, so all bets are off if you take those numbers as gospel truth. A little skepticism goes a long way when it comes to water test kits in planted tanks.


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## Amaralluis (Oct 21, 2005)

Thanks for the reply.

I dont know how accurate the test kit is to be honest.
It is well possible that high nitrates might have been the cause of my shrimp deaths. The only proof that I have is that i've seen them die when I tried to raise co2 and ph was below or equal 6.8.
This is my experience.
I will definetly reduce to 1/2tsp kno3 and see if it improves things.


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