Wet Skimming When Caron Dosing?

[BigMax]

I have been carbon dosing (vodka/vinegar) for about a year, with little impact on nitrate levels. My skimmate is very dark—should I be aiming for a wetter skim (tea-colored) when carbon dosing? I've heard comments to that effect and am curious about others' recommendations.

 

[Randy Holmes-Farley Verified Community Expert]

that might help, but it may also be you just need more organic.

Can you give more details on nitrate, phosphate, and what amount of what organic is added to what size tank?

 

[BigMax]

that might help, but it may also be you just need more organic.

Can you give more details on nitrate, phosphate, and what amount of what organic is added to what size tank?

The tank has been running for 30 years—it's a 350-gallon FOWLR system. I currently have only a 12-inch Naso Tang in the tank, which I've had for over 13 years. He eats about 50 3mm pellets twice a day; he's a pig.
My nitrates are embarrassingly high, around 400 ppm, though all fish have done very well in that environment regardless. The average lifespan of fish in this tank over the 30 years has been about 10 years.

I have a Harlequin Tusk and an Emperor Angelfish in quarantine (for 6 months now), which I plan to add to the tank shortly. I plan to do a 140-gallon water change about a week before introducing the new specimens.

I'm dosing a NOPOX-equivalent mix (vodka and vinegar) at about 50 ml per day. This was reduced from 68 ml, as I was getting white slime in the tank at that higher dose. About every 4–5 months, I also get a large bloom of stringy white sponge growth, which pops up, and goes away after about 4 weeks. I once dumped some water from my reef tank into the FOWLR system and assumed that's the source.

Skimmer is a Reef Octopus 220-int (good size).

My guess is you'll recommend getting the nitrates well below 100 ppm in order to manage the system without excessive dosing? The challenge is balancing between the white slime growth and seeing any real impact to nitrate reduction.

Thx

 

[Dan_P]

The tank has been running for 30 years—it's a 350-gallon FOWLR system. I currently have only a 12-inch Naso Tang in the tank, which I've had for over 13 years. He eats about 50 3mm pellets twice a day; he's a pig.
My nitrates are embarrassingly high, around 400 ppm, though all fish have done very well in that environment regardless. The average lifespan of fish in this tank over the 30 years has been about 10 years.

I have a Harlequin Tusk and an Emperor Angelfish in quarantine (for 6 months now), which I plan to add to the tank shortly. I plan to do a 140-gallon water change about a week before introducing the new specimens.

I'm dosing a NOPOX-equivalent mix (vodka and vinegar) at about 50 ml per day. This was reduced from 68 ml, as I was getting white slime in the tank at that higher dose. About every 4–5 months, I also get a large bloom of stringy white sponge growth. I once dumped some water from my reef tank into the FOWLR system and assumed that's the source.

Skimmer is a Reef Octopus 220-int (good size).

My guess is you'll recommend getting the nitrates well below 100 ppm in order to manage the system without excessive dosing? The challenge is balancing between the white slime growth and seeing any real impact to nitrate reduction.

Thx

After a year of dosing, it might be time to try another method. There might be a way to investigate this stall, but first, several questions.

What is your DIY NOPOX recipe?

What is the phosphate level?

With NO3 that high, I would check the nitrite level because small amounts can cause nitrate tests to read high.

How are you measuring 400 ppm nitrate? What kit? How are you diluting the aquarium water?

 

[BigMax]

After a year of dosing, it might be time to try another method. There might be a way to investigate this stall, but first, several questions.

What is your DIY NOPOX recipe?

What is the phosphate level?

With NO3 that high, I would check the nitrite level because small amounts can cause nitrate tests to read high.

How are you measuring 400 ppm nitrate? What kit? How are you diluting the aquarium water?

NOPOX Recipe (in parts):

• 37.5 Vodka
• 50.0 Vinegar
• 12.5 Deionized (DI) Water

Phosphate: Not yet tested.

Nitrate (NO₃):

• Tested using ATI a month ago and also two years prior.
• Also tested using a Hanna nitrate tester with a 10:1 dilution.

I should have mentioned this earlier, but my main focus is on NOPOX usage. I added a 20-gallon Chaeto sump about six months ago. To support Chaeto growth, I dose 2 mg of iron daily. This is one reason I had the ATI test completed, their results showed no detectable trace of iron (Fe).

 

[Dan_P]

NOPOX Recipe (in parts):

• 37.5 Vodka
• 50.0 Vinegar
• 12.5 Deionized (DI) Water

Phosphate: Not yet tested.

Nitrate (NO₃):

• Tested using ATI a month ago and also two years prior.
• Also tested using a Hanna nitrate tester with a 10:1 dilution.

I should have mentioned this earlier, but my main focus is on NOPOX usage. I added a 20-gallon Chaeto sump about six months ago. To support Chaeto growth, I dose 2 mg of iron daily. This is one reason I had the ATI test completed, their results showed no detectable trace of iron (Fe).

Thanks for the additional information. Here are some ideas.

The DIY NOPOX dose you are currently adding contains a little less than 1/2 of the maximum vodka dose (1/8 mL per gallon of aquarium water) and 7% of the maximum vinegar dose 1 mL per gallon). These maximum doses are rough reference points where if things are working, the 1 mL vinegar dose results in a 2 ppm reduction and the 1/8 mL dose of vodka a 3.1 ppm nitrate reduction. If things were working, you should see with your current dose about a 1.5 ppm nitrate reduction per dose. Given that you would like to remove more than 300 ppm nitrate, you would need to dose at least 200 days, and that’s if things work correctly. Dosing tends to take longer than this. Yours seems to have just stalled and grows only slime when you try a higher dose. This situation does not seem unusual.

If phosphate is depleted, dosing does not work well. Bacteria need about 0.1 ppm phosphate for every 1 ppm nitrate consumed (approximately)

Good move on using macro algae for nitrate reduction. I am an Ulva (sea lettuce) fan. It removes more nitrate than Cheatomorpha but I read that after selecting Ulva for my 10 gallon algae pond. Also, I was able to fill up the pond with Ulva but never was able to grow Cheato.

I use CheatoGro (1 daily dose per week. Higher doses sickened my snails) to keep the Ulva healthy (dark green with stiff “leaves”) and hedge my bet with a weekly iron dose.

Forget about ICP to measure iron. Iron doesn’t last very long in the aquarium. I used the Hanna Iron Checker (the most sensitive one they have) to follow the concentration of iron and found that it is mostly gone in 24 hours.

 

[BigMax]

Thanks for the additional information. Here are some ideas.

The DIY NOPOX dose you are currently adding contains a little less than 1/2 of the maximum vodka dose (1/8 mL per gallon of aquarium water) and 7% of the maximum vinegar dose 1 mL per gallon). These maximum doses are rough reference points where if things are working, the 1 mL vinegar dose results in a 2 ppm reduction and the 1/8 mL dose of vodka a 3.1 ppm nitrate reduction. If things were working, you should see with your current dose about a 1.5 ppm nitrate reduction per dose. Given that you would like to remove more than 300 ppm nitrate, you would need to dose at least 200 days, and that’s if things work correctly. Dosing tends to take longer than this. Yours seems to have just stalled and grows only slime when you try a higher dose. This situation does not seem unusual.

If phosphate is depleted, dosing does not work well. Bacteria need about 0.1 ppm phosphate for every 1 ppm nitrate consumed (approximately)

Good move on using macro algae for nitrate reduction. I am an Ulva (sea lettuce) fan. It removes more nitrate than Cheatomorpha but I read that after selecting Ulva for my 10 gallon algae pond. Also, I was able to fill up the pond with Ulva but never was able to grow Cheato.

I use CheatoGro (1 daily dose per week. Higher doses sickened my snails) to keep the Ulva healthy (dark green with stiff “leaves”) and hedge my bet with a weekly iron dose.

Forget about ICP to measure iron. Iron doesn’t last very long in the aquarium. I used the Hanna Iron Checker (the most sensitive one they have) to follow the concentration of iron and found that it is mostly gone in 24 hours.

Thanks for your perspective and recommendations!

I will test my phosphate today.....I always assumed it was high as well, but we'll see.

 

[BigMax]

Thanks for the additional information. Here are some ideas.

The DIY NOPOX dose you are currently adding contains a little less than 1/2 of the maximum vodka dose (1/8 mL per gallon of aquarium water) and 7% of the maximum vinegar dose 1 mL per gallon). These maximum doses are rough reference points where if things are working, the 1 mL vinegar dose results in a 2 ppm reduction and the 1/8 mL dose of vodka a 3.1 ppm nitrate reduction. If things were working, you should see with your current dose about a 1.5 ppm nitrate reduction per dose. Given that you would like to remove more than 300 ppm nitrate, you would need to dose at least 200 days, and that’s if things work correctly. Dosing tends to take longer than this. Yours seems to have just stalled and grows only slime when you try a higher dose. This situation does not seem unusual.

If phosphate is depleted, dosing does not work well. Bacteria need about 0.1 ppm phosphate for every 1 ppm nitrate consumed (approximately)

Good move on using macro algae for nitrate reduction. I am an Ulva (sea lettuce) fan. It removes more nitrate than Cheatomorpha but I read that after selecting Ulva for my 10 gallon algae pond. Also, I was able to fill up the pond with Ulva but never was able to grow Cheato.

I use CheatoGro (1 daily dose per week. Higher doses sickened my snails) to keep the Ulva healthy (dark green with stiff “leaves”) and hedge my bet with a weekly iron dose.

Forget about ICP to measure iron. Iron doesn’t last very long in the aquarium. I used the Hanna Iron Checker (the most sensitive one they have) to follow the concentration of iron and found that it is mostly gone in 24 hours.

I checked phosphate / phosphorus and confirmed with ATI testing it's undetectable, a surprise to me. I'm looking at ordering this from Amazon. Is it acceptable?

Sodium Phosphate Monobasic / 4 Ounce Bottle / 98+% Pure Reagent Grade/Fine Powder (Loudwolf)​

At a 10:1 ratio that would be 40ppm phosphate. :) So I'll add enough to just go over the scale of the Hanna ULR checker at about 1ppm. I wonder if with the huge imbalance there will be any improvement, or if it will give things a jump start. A second alternative would be to calculate the additive amount to bring phosphate up to 4 ppm over a month and measure the downward trend to 1ppm.

As it's a FOWLR tank I only have 50 watt LED strip over tank, which is a blessing. I couldn't imagine the algae bloom if there was more lighting.

Thx for the help....

 

[Randy Holmes-Farley Verified Community Expert]

I checked phosphate / phosphorus and confirmed with ATI testing it's undetectable, a surprise to me. I'm looking at ordering this from Amazon. Is it acceptable?

Sodium Phosphate Monobasic / 4 Ounce Bottle / 98+% Pure Reagent Grade/Fine Powder (Loudwolf)​

At a 10:1 ratio that would be 40ppm phosphate. :) So I'll add enough to just go over the scale of the Hanna ULR checker at about 1ppm. I wonder if with the huge imbalance there will be any improvement, or if it will give things a jump start. A second alternative would be to calculate the additive amount to bring phosphate up to 4 ppm over a month and measure the downward trend to 1ppm.

As it's a FOWLR tank I only have 50 watt LED strip over tank, which is a blessing. I couldn't imagine the algae bloom if there was more lighting.

Thx for the help....

Yes, that’s a fine choice for phosphate dosing.

 

[Dan_P]

I checked phosphate / phosphorus and confirmed with ATI testing it's undetectable, a surprise to me. I'm looking at ordering this from Amazon. Is it acceptable?

Sodium Phosphate Monobasic / 4 Ounce Bottle / 98+% Pure Reagent Grade/Fine Powder (Loudwolf)​

At a 10:1 ratio that would be 40ppm phosphate. :) So I'll add enough to just go over the scale of the Hanna ULR checker at about 1ppm. I wonder if with the huge imbalance there will be any improvement, or if it will give things a jump start. A second alternative would be to calculate the additive amount to bring phosphate up to 4 ppm over a month and measure the downward trend to 1ppm.

As it's a FOWLR tank I only have 50 watt LED strip over tank, which is a blessing. I couldn't imagine the algae bloom if there was more lighting.

Thx for the help....

Wow, undetectable phosphate! Hopefully you won’t open the gates of hell when you dose phosphate. Maybe, stand back when you dose :-). Going slowly at first might be prudent.

 

[BigMax]

I just purchased new Hanna phosphate reagent packets to re-test my FOWLR system after receiving puzzling results from ATI. According to ATI, my phosphate (PO₄) and phosphorus (PO₄-P) levels were undetectable—essentially zero, while nitrate measured at 645 mg/L. That combination seems highly improbable, if not impossible. As expected, my Hanna checker showed phosphate levels off the charts.

Does anyone have thoughts or similar experiences with ATI testing ?

Additionally, I dose 2 mg of iron daily to support Chaeto growth, yet ATI reported iron as undetectable. If I recall correctly Randy Holmes-Farley once mentioned that ATI’s iron test might be unreliable, though I might be misremembering. Has anyone else encountered this discrepancy? All the Fe may be consumed, but now I'm questioning things.

And yes, I plan to reduce nitrates just below 100ppm.