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Discussion Starter · #1 ·
Hi all,

Lately I notice at the end of each week prior to my 50% WC my nitrates have been sky high, like 80ppm high. I decided to test my tap and low and behold I now have 5ppm nitrates in it when it previously had none. I'm assuming I have to change my fert amounts. I'm not sure how much of what to leave out honestly so I'm hoping someone can steer me in to an adjustment. Below is my dosing schedule. My tank is a 46 gallon bow front. I have high light and pressurized co2. I'd say I'm moderately to moderately high planted.

Dosing schedule that I mix in 500ml bottles. I dose 60ml micro/macro every other day mon-sat. Sunday is 50% WC and no feeding/no ferts.

KNO3
To reach your target of 7.5 ppm NO3 you will need to add 17.745 g KNO3 to your 500.0 mL dosing container. Add 60.0 mL of that mix to your 46.0 US gal aquarium to yield
Element ppm/degree
K 4.73
N 1.69
NO3 7.50

K2SO4
To reach your target of 7.5 ppm K you will need to add 24.253 g K2SO4 to your 500.0 mL dosing container. Add 60.0 mL of that mix to your 46.0 US gal aquarium to yield
Element ppm/degree
K 7.50
S 3.08

KH2PO4
To reach your target of 1.3 ppm PO4 you will need to add 2.703 g KH2PO4 to your 500.0 mL dosing container. Add 60.0 mL of that mix to your 46.0 US gal aquarium to yield
Element ppm/degree
K 0.54
P 0.42
PO4 1.30

Plantex CSM+B
To reach your target of 0.5 ppm Fe you will need to add 11.111 g Plantex CSM+B to your 500.0 mL dosing container. Add 60.0 mL of that mix to your 46.0 US gal aquarium to yield
Element ppm/degree
B 0.09
Cu 0.01
Fe 0.50
Mg 0.11
Mn 0.14
Mo 0.0038
Zn 0.03
dGH 0.02
 

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Just start using less KNO3. Your plants aren't up taking enough N to keep the levels at the 20ish ppm you want to hold so just lower that component a bit until you end up closer to it at the end of the week. If your K levels are to low after reducing the KNO3 increase the K2SO4 a tad to compensate.
 

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Are you doing a 50% weekly water change?

If so, the obvious answer to me would be to reduce your KNO3 dose by at least 50% (30ml). Most likely it's a combination of your NO3 level in the tap and feeding. Check out this projection application. If you choose the optional section you'll see other selections. Play with the "Tap/waterchange water has known concentration of Stuff" and "Amount of food added each week" option. You may see the problem. Never the less. I would decreases the KNO3 dose by 50% and see how it goes. Btw, you may want to calibrate your Nitrate test just to make sure it's accurate.
 

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Actually I'm surprised that they didn't add this. You make up for the lost K when you cut the KNO3 by 50% by adding K2SO4. It's close enough to just add the same amount you took from the KNO3. Example only: if you reduced the KNO3 from 1/4 to 1/8 tp
then add 1/8 tsp of K2SO4. The K is an easy nutrient to have not enough of but hard to overdose.
 

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5 ppm of nitrate in the tap water is the same as increasing your weekly nitrate dosage by 2.5 ppm. That is not going to ever drive the nitrates in the tank water to 80 ppm, if you do weekly 50% water changes. Either your nitrate measurement is wrong, or you have a very overstocked tank, with minimal planting. I think it is your nitrate measurement that is wrong.
 

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Discussion Starter · #6 ·
Thanks for all the info. I'm at a loss for what is causing this then.

Hoppy, I'm definitely not overstocked if anything I'm understocked. The test kit shows its good till 2016. It's possible it can still be bad?

My filter pre-sponge and filter floss could go for changing but it's not dirty enough to drive the nitrates that high I don't think. I did see a bunch of white balls from root tabs on the substrate surface could that do it? I've since pushed them back down though.
Here is a pic of my tank from Sunday. I did a massive trim and thin down last week but the nitrate issue has been a month now.




Sent from my XT1060 using Tapatalk
 

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Every time I've tested for nitrates the vial shows they're over 100ppm. Obviously there is something wrong with the test considering a few years ago I tested when the plants were showing obvious signs of nitrogen deficiency and the tests still showed 100ppm. Needless to say I was pretty confused. Ignoring the test completely and going with my gut feeling, I doubled my dose of kno3 and the plants began to recover beautifully within a few weeks. So personally I wouldn't trust the test too much. I don't know what the test was picking up, but something was obviously screwing it up. I'd crank up your co2 and let whatever nitrates are left in your tank get sucked up by the plants. Another thing is to look up your towns water report from the water company and see what they list the nitrate content of your tap is.
 

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Discussion Starter · #8 ·
Hrm, I'll pick up another test kit and see if that makes a difference in my readings. It's really driving me crazy and I don't want to cause any undue stress on my plants or fish. Fish seem fine though, plants keep growing. I just worry that it could be from the root tabs coming up, or maybe I used too many, though I don't think I did.

CO2 is cranked as high as it can go, just a few ticks below fish gasping level. I get pearling nightly on my plants as well.

My town shows nitrates at 1.2 ppm so since my test kit shows 5+ppm from the tap, I guess it could certainly be off, but it's really not that off that the 80ppm I'm seeing in my tank isn't worrisome.

Every time I've tested for nitrates the vial shows they're over 100ppm. Obviously there is something wrong with the test considering a few years ago I tested when the plants were showing obvious signs of nitrogen deficiency and the tests still showed 100ppm. Needless to say I was pretty confused. Ignoring the test completely and going with my gut feeling, I doubled my dose of kno3 and the plants began to recover beautifully within a few weeks. So personally I wouldn't trust the test too much. I don't know what the test was picking up, but something was obviously screwing it up. I'd crank up your co2 and let whatever nitrates are left in your tank get sucked up by the plants. Another thing is to look up your towns water report from the water company and see what they list the nitrate content of your tap is.
 

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Have read from the guru's that nitrate test result's are suspect unless and until one calibrates them.
Believe one can google "calibrating nitrate test's" and maybe receive some enlightenment.
Last time I tested (uncalibrated) my own nitrate level's read 80ppm or more yet fishes,shrimp's,plant's,are still thriving a year later.
50% water change each week .
 

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Hrm, I'll pick up another test kit and see if that makes a difference in my readings. It's really driving me crazy and I don't want to cause any undue stress on my plants or fish. Fish seem fine though, plants keep growing. I just worry that it could be from the root tabs coming up, or maybe I used too many, though I don't think I did.

CO2 is cranked as high as it can go, just a few ticks below fish gasping level. I get pearling nightly on my plants as well.

My town shows nitrates at 1.2 ppm so since my test kit shows 5+ppm from the tap, I guess it could certainly be off, but it's really not that off that the 80ppm I'm seeing in my tank isn't worrisome.
That's the calibrator right there. If your town shows 1.2 and your test shows five than by some calculations your actual reading is more like 20ppms. Your test is reading 4 ppm more than what the water company is getting, And my guess is that they're probably using much more accurate tests lol.
 

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Discussion Starter · #11 ·
I completely agree. I'm going to give it another go tonight and shake the crap out of the bottle, though I did bang it like crazy on the wall too last time. I figure I'll do a sample test also on some distilled water which should register zero and see what that shows. I feel much better about my tank right now.

Like I said, there was no signs of issues with fish or plants, I was just really confused by the off the charts reading. Even water changes weren't helping.

That's the calibrator right there. If your town shows 1.2 and your test shows five than by some calculations your actual reading is more like 20ppms. Your test is reading 4 ppm more than what the water company is getting, And my guess is that they're probably using much more accurate tests lol.
 

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Discussion Starter · #13 ·
What's the fix? Will me pushing the pellets from the root tabs back down keep it from leeching in the water?

This probably accounts for a lot of this problem.

I would suggest calibrating the test though. Water reports are only valid for the sample they collected. Levels can change seasonally.

Calibrating Test Kits - for non-Chemists
 

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Discussion Starter · #14 ·
OK so I've done everything I can think of here and I now have a conspiracy theory.

So far I've done two 50% water changes this week and a few 25% ones. I've pushed all root tab pellets I saw on the surface all the way to the bottom of the glass under the substrate. I've not fed the fish for 3 days. I stopped dosing no3 for this week. I also changed out my filter floss and the pre-filter blocks. My nitrates are still reading around 80ppm.

So here's my conspiracy theory/question. I've noticed my whole MTS colony die off the last month of so. My substrate looks like a MTS shell graveyard. All shells on the surface are empty, my peacock gudgeons loves them and picks them off any chance they get. What are the chances though there are a lot of dead ones under the substrate that never surfaced and are rotting? Is that something that is a possibility? If so, well damn I'd have to tear the whole tank down to get them out. Any other options?
 
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