Overdosed??

[Blackwood]

I added 2 teaspoons of Grant's Stump Remover (KN03) to my 125 gallon tank last night. I tested Nitrate and Phospate today.

Nitrate is at either 80 or 160 PPM, can't tell on the colors. Yes, I know this is way high. I have no idea why it went from 0 to that high with a small dose. Will 100ish PPM do any real damage to my tank?

Phosphate is at about 4.0. Is that good?

Nitrate is my main concern obviously.

 

[Lonewolfblue]

Do a PWC to get it down a little. You don't really want to go over 2ppm phosphates or you may have complications. That hight of nitrates can also creat complications.

 

[czcz]

According to Chuck's calc you dosed around 15ppm NO3 with 2teaspoons, which is good. Could the test be faulty? Any chance you added 2tablespoons (~45ppm NO3)?

Agree about dropping PO4. As LWB said a large water change to reset the system is the best course of action after possible dosing issues.

 

[Blackwood]

I used Chuck's Calc to figure the dosage. It's showing very high with a brand new Aquarium Pharmaceuticals liquid test. I followed the instructions exactly and it showed very high. At least 80ppm.

Either the dosing is way off with the Grant's Stump Remover somehow, or the test is bad. I'll test it again tomorrow (Wed) and if it still reads high, I'll do a 50% water change. That'll brind down the Phosphate too.

 

[czcz]

I used Grants for months and had it measure (AP) the same as Greg Watson's agricultural grade KNO3 fwiw. I also have some KNO3 a club member sourced from a chemical supply. I don't think there's enough difference in impurity level in these that we have to worry about it for our purposes.

 

[malkore]

What did the water test prior to dosing the stump remover?

and, does the grants list ingredients as: Potassium nitrate and nothing else?

did you literally shake reagent 2 for 30 seconds to a minute?
did you literally shake the vial after adding reagent 2 for 30-45 seconds?

the NO3 test gets less accurate the less you shake it, IMO. and its usually only inaccurate at very low levels (under 15ppm).

 

[Blackwood]

I shook it exactly as the directions stated. Reagent 2 for 30 seconds, vial with both added for 1 full minute. Waited 5 full minutes for it to 'develope'.

I'll do the water change tonight and see what it measures at.

 

[fish_4_all]

I was at Home Depot yesterday and actually found stump remover. FWIW, I have 1 pound of KNO3 I ordered from Gregs and the container at HomeDepot was 5 pounds but the overall volume seemed to be a lot less with the stump remover. Maybe it is compressed or concentrated. I would find a way to weigh it to make sure it is an accurate amount that you are adding using a teaspoon. If it doesn't weigh out right, then modify your dosing and it should work for you. If it weighs out right then give this a try:

Take 1 tsp and dissolve it in 350ml of bottled water. Take 1 ml of this solution and put it in 1 liter of bottled water. This new solution should be right at 10 ppm. If it isn't right at 10ppm then your test kit is bad. My test kit gave me 10 ppm or just under. I also tested this without shaking the #2 bottle and got less than 5ppm.

This worked for me and I did the calculations so please recheck my work. I have been known to make errors, just ask my wife. :?

 

[Blackwood]

I have a pound of KN03 on order from Gregwatson.com. I'm hoping it shipped Monday. I plan on using that instead of the stump remover. I only bought the stump remover as an interim KN03 source until the order from Greg came in.

I'll post my measurements after the 50% water change tonight.

 

[czcz]

re stump remover, FYI the only two brands I am aware of that verified to be "pure" KNO3 are Grant's and Greenlight. I remember a hydroponics forum that had emails from their company reps verifying this, but I can no longer find the bookmark.

Blackwood, if you can a 75% water change or two 50% changes should be better to reset your current levels. Using fish_4_all's solution to test the test kit would be wise. (Though imo you should dilute this more, say 5mL in 5L, since 1mL dosing for calibration is difficult without a pipette.)

 

[fish_4_all]

Good idea CZ, I used 1 ml because I have alot of old insulin cyringes I use for fishing a lot and that is what I used. 5ml would be a lot easier.

What brand is the stump remover? Your test results could be useful for others that don't need to order a lot of different fertilizers but just need KNO3

 

[Blackwood]

Well, this is sort of an odd new/bad news update I guess.

I tested the N03 before the water change and it looked like it was around 40ppm, but was hard to tell.

I did a 20% water change thinking that if it was only 40, that would bring it down noticably. After the water change, I let it circulate for a couple hours to even out and retested.

The color comes out so red that it has to be 160ppm, and I just didn't see the color right the first test today.

The odd thing is that with a 20% water change, my Phosphate went from 4.0 to 2.0. I'm confused on why the phosphate got cut by 50%, but the Nitrate not at all.

I used 2 teaspoons (not tablespoon) of Grant's Stump Remover (Yes, it's Grant's, not Green Top or any other) dissolved into 750ml of water and dumped into the sump. According to Chuck's dosing chart, that should have brought me up to 15ppm.

Hmm, I'm wondering if my tapwater is really high in Nitrates. I'll have to go test that separately.

<Edit> Water straight from the tap is 3-4 ppm. Slightly lighter than the color for 5.0 ppm, so that's definitely not the problem.

I'll do a 60%ish water change tomorrow when I get home from work and see what that does.

I put some new driftwood in Sunday too. Would that cause a Nitrate problem?

What will Nitrate >160ppm do to my tank? Will it kill fish, or just feed the hell out of the plants?

I've lost two fish in the last few days. One Red Molly, and an Ottocinclus today. Oh, and two Red Claw crabs that crawled out of the tank because I don't have it sealed properly for crabs. I guess you can call an open top not sealed....

 

[czcz]

It is expected that the phosphates drop with nitrate (and other nutrients) available. Maybe it just dropped some between the test before the 20% water change and after? It is said PO4 is an inaccurate test, and that we should use them more as indicators of uptake than for specific levels. I think it is likely the nitrate lowered as well, but that the reds on the AP kit that high are near impossible to tell apart.

Dead and rotting fish and excess fish food are two causes of high nitrates. High nitrates are reported to stunt fish growth and lower their immune systems. In a planted tank, NO3 >40ppm leads to algae for some, and is not a problem for others.

What were your nitrate levels like before starting dosing?

 

[Blackwood]

Well, after a 65% water change last night, N03 is down to 20ppm. I can easily live with that.

Hopefully the plants will start to recover and I won't lose any fish. I'll have to retest Phosphate tonight to see if there's any left in the tank after that major of a water change.


Thanks for the help and suggestions.

 

[7Enigma]

Blackwood,

If your tank has ~40ppm of nitrAte naturally, why would you add more nitrAte to the tank? Are you dosing mainly for the potassium? If that is the case get some potassium sulfate (K2SO4) instead. You'll only be adding potassium then and the added sulfates are not a problem. My tank seems to be similar to yours.

I have a fully stocked tank and pretty well planted. Because of this my nitrAte level stays most times around 10ppm and occassionally I have to add slight amounts of potassium nitrAte to get that level up closer to 15-20ppm. The rest of the week I'll add the potassium sulfate since I don't want extra nitrAte, just the potassium.

The other thing I wanted to mention was the ppm levels with your water changes. Unless the tank water didn't mix properly between the time you did the water change and the test a 20% water change will only lower the phosphate and nitrAte by 20%. Going from 4ppm to 2ppm phosphate with a 20% PWC is not possible. Either the test is inaccurate at that high level (if this is the AP kit it is hard to tell anything over 1ppm with a good degree of accuracy), because a 20% PWC should have only lowered that phosphate 0.8ppm to 3.2ppm.

As for the nitrAte a 20% PWC very well could not have shown a difference especially if your OVER the detectable level. But again this can't happen if you did indeed only add 2 teaspoons to the tank.

What you should do is a serial dilution (or normal dilution) to get a better idea of exactly how much of each your seeing. Take a small dixie cup or shot glass and fill it with tap water. Dump this into another larger clean glass/cup. Now using the same dixie cup or shot glass fill it with tank water (to the exact same level as the tap water) and dump this into the larger glass. Mix.

What you have done is diluted the tank water 1:1. Now go and retest your nitrAte and phosphate. If your tank water indeed has ~2ppm of phosphate you will read ~1ppm on the test (since you only have 1/2 the tank water). If your tank water indeed has more than 100ppm nitrAte you will read more than 50ppm nitrAte.

If you still get difficult to read numbers use an extra shot or 2 of tap water into the big cup. Let me write out a quick example if this is confusing:

You think you have 160ppm nitrAte. You run the nitrAte test and its blood red, so there is no way you can tell if you have 120ppm or 1000ppm. So you take 1 shot of tank water and 3 shots of tap water and mix in a cup. Then you take 5ml of that water to do your nitrAte test. Your nitrAte test says that you have 30ppm of nitrAte. Because you just did a 1:4 dilution (1 part tank water to 3 parts tap water) you multiply the 30ppm by 4. This tells you than your tank has ~120ppm nitrAte.

This is a much more accurate way of measuring high levels in the tanks since a lot of test kits can easily show color differences on the low end (say for the nitrAte a yellow, orange, red) instead of the common high end (red, red, deep red) which is all but impossible to tell the difference. The same is true for the phosphate kit (AP kit is easy to tell at under 1ppm since it goes yellow, yellow-green, green).

 

[Purrbox]

One thing I'd like to add to what 7Enigma has already said about diluting the tank water to get better test readings. Only use tap water if it has 0 Nitrates. If you've got Nitrates in your tap water you would be better off getting some RO water from the grocery store.

 

[7Enigma]

Good point Purrbox. I see he does have 3-5ppm in his tap water. A single dilution would not make much difference, but if he has to do 3-4 dilutions then definately use some distilled or RO water as that small amount in the tap water gets compounded at each dilution and would make the numbers very inaccurate.

 

[Blackwood]

Thanks for the info guys. I should be getting good KN03 from GregWatson tomorrow as well as the general nutrient mix.

I'll do the testing then. I have 5 gallons of RO from the LFS, so I'll dilute with that.

Thanks for the info. It is much appreciated.



Blackwood