Carbon dosing questions

[Randy Holmes-Farley]

Is there a reason the phosphate would drop so drastically without nitrates falling at all? That's over 0.2ppm phosphate removed and 0 nitrates removed.

From carbon dosing? No, that could only be test error (assuming you are not adding N somehow).

But other processes reduce phosphate and not nitrate, such as binding to mineral surfaces.

 

[Oregon Grown Reef]

From carbon dosing? No, that could only be test error (assuming you are not adding N somehow).

But other processes reduce phosphate and not nitrate, such as binding to mineral surfaces.

I am feeding Reef Nutrition TDO Chroma Boost and only once per day. The fish consume it within 1-2 minutes each time. The rocks have been in there for some time (1.5 years), so I would assume at this point they're saturated. There was a large amount of thick coralline that I scraped off the back glass this last week. Would the phosphate bind to the unexposed coralline (ie the part attached to the glass and not directly exposed to water)? I removed 90% of it within a day.

 

[Randy Holmes-Farley]

I am feeding Reef Nutrition TDO Chroma Boost and only once per day. The fish consume it within 1-2 minutes each time. The rocks have been in there for some time (1.5 years), so I would assume at this point they're saturated. There was a large amount of thick coralline that I scraped off the back glass this last week. Would the phosphate bind to the unexposed coralline (ie the part attached to the glass and not directly exposed to water)? I removed 90% of it within a day.

Can you clarify what you did during this time that phosphate dropped by 0.2 ppm? It might just be test error and wouldn't be worth agonizing over.

I suppose the back side of the coralline might have exposed calcium carbonate that bound phosphate, but I'm a bit skeptical of that big of an effect.

 

[Oregon Grown Reef]

Can you clarify what you did during this time that phosphate dropped by 0.2 ppm? It might just be test error and wouldn't be worth agonizing over.

I suppose the back side of the coralline might have exposed calcium carbonate that bound phosphate, but I'm a bit skeptical of that big of an effect.

As am I. I did a 10% water change. Other than that, I've only done the carbon dosing. It is possible that I did the test improperly. I inverted the test vial for 2 minutes today instead of "gently" shaking it like the instructions say. I read that someone here spoke to a Hanna rep that told them that inverting it is what actually needs to be done. Now I'm not so certain.

 

[Dan_P]

Is there a reason the phosphate would drop so drastically without nitrates falling at all? That's over 0.2ppm phosphate removed and 0 nitrates removed.

I have several thoughts for this observation. Our test kit results have a substantial standard deviation. I regard a no change in nitrate level to mean that the nitrate change could have been low, maybe 1 or 2 ppm. Another thing to keep in mind is that a no change in nitrate could mean ammonia, nitrite or some other nitrogen source was consumed instead of nitrate. The last thought is that microorganisms also consume more PO4 then they need, known as luxury consumption. Or it could be a combination of all three of these ideas or something entirely different.

What would be strange is if you all of sudden needed to dose 0.1 PO4 every day but nitrate did not budge. Then we would have to do some head scratching.

 

[HB AL]

I have higher nutrients in my 40b w/ a 29 gal sump (total of 50 gal water volume). My nitrates are 24.9 and my phosphates are 0.21. The nitrates were much higher recently, but I did a few water changes to bring them down to these levels. I started carbon dosing (vinegar) today following the dosing chart on reefkeeping.com.

Questions are:

1. How often should I test nitrate and phosphate? Do I need to test more often up front and less once I reach acceptable levels (5-10 nitrate, 0.05-0.1 phosphate)? I was reading that some people don't see improvements for several months. Not sure if I can stick with testing every day for that long.
For now till you figure things out atleast every other day.
2. Some places say that you cut back dosing amounts up to 50% once levels are achieved. This seems like a lot to cut back. Is that correct?

3. Is GAC required to use while carbon dosing?

4. I've seen people dose this with kalkwasser. As my alk consumption rises from all of the glorious growth I'll get as a result of carbon dosing, I'll want to start adding kalkwasser.
Per reefkeeping.com, "When dripping vinegar it is best to not dilute it too much or store the diluted vinegar too long since diluted vinegar can be broken down by bacteria in the dispensing vessel reducing the amount of carbon dosed. Dilution and delivery the same day is fine, but a 10% vinegar plus 90% water solution is not likely stable over the course of a week or two."
Would I be able to add vinegar to a 5 gallon bucket of kalk and use it over a month or more without worrying about it being broken down? If this isn't how it's done, what would you recommend?

1- For now till you figure things out atleast every other day.
2- once you get them down to where you want, you would lower the dose to maintain them at those levels, because you need to keep them stable at whatever levels your looking to achieve. You don't want to keep dosing to much or to little to avoid spikes or lows.

3- I run gac and phosgaurd 24/7 but every tanks different, I have alot of food consuming fish and lots of corals of all types.
4- I would dose them separately.
With that said listen to the guys above and follow there advice. I dose NoPox and have settled on 30 to 40 ml a day but I will forget a day here and there not a big deal. I dose everything manually, I have no dosers or computers running and checking my system. Now I've reached the point with my current tank and it's now on "cruise control " and havnt tested ANYTHING in 3 months+ as everytime I test things are right around fine levels and the corals and other things I look for will let me know if I need to test which when I do I test everything. I dont suggest you do that now or ever, as it took decades for me to get to that point. I really like my fish more than the corals so I figure if the water is good enough for the corals to be thriving it's excellent for the fish. I keep and do things really simple, my highest piece of equipment is either the skimmer or the lights which I set and forget about as everything is simple yet effective which in turn doesn't make the tank feel like a chore or just too much work which is something people do and burn out quick because they make things more difficult than they really are. My biggest chore with my tank is feeding my fish (I don't feed any coral specific food) which I do every other day, between my Japanese Dragon Eel, my large Broomtail Wrasse, 7 triggers, a grouper, tangs, and a few other types of fish, I call it controlled "chaos"! Oh by the way I don't do water changes either. Good luck and with time and the good advice from some of the guys you too will figure things out just be patient and keep it simple.

 

[Oregon Grown Reef]

I have several thoughts for this observation. Our test kit results have a substantial standard deviation. I regard a no change in nitrate level to mean that the nitrate change could have been low, maybe 1 or 2 ppm. Another thing to keep in mind is that a no change in nitrate could mean ammonia, nitrite or some other nitrogen source was consumed instead of nitrate. The last thought is that microorganisms also consume more PO4 then they need, known as luxury consumption. Or it could be a combination of all three of these ideas or something entirely different.

What would be strange is if you all of sudden needed to dose 0.1 PO4 every day but nitrate did not budge. Then we would have to do some head scratching.

I'll admit that I haven't been very good with all of my testing. Since I have only 1 LPS frag and some zoas in the tank as of right now, I haven't been testing the alkalinity. I'll be testing calcium and magnesium as well as adding some sodium bicarbonate over the next week to get the alkalinity up to 8.5. It is a fresh bottle of alk reagent that is going to be stored in the refrigerator per the findings of another member on here. Below are the levels of nitrate I've been logging and the sparce phosphate testing. The drop in nitrate is from the 10% water change. Since I haven't tested phosphate for a while, it's hard to speculate what could have caused it or at what point. I'll confirm with a Hanna rep tomorrow on proper procedure for doing the tests. I thought I was doing them properly, but the change in my method today could very well be the cause of the reading. I should have been testing all parameters daily since implementing carbon dosing. As they say, hindsight is 20/20. Once I get some more data, I'll post an update. For now I'm going to stick with it and dose phosphate as needed, if at all.

 

[Oregon Grown Reef]

Oops, double post.

 

[Oregon Grown Reef]

The phosphate dropping was truly a head scratcher. I had to dose neophos a few days in a row to raise it to 0.07ppm. It's been steady after 3 days since my last dose. Nitrate remains stable at 27ppm +/- 0.5ppm (within test margins). I've increased dosing distilled white vinegar to 35ml and will continue to monitor for a few days before increasing it another 5ml. I have to keep in mind that vinegar is 8 times less potent than vodka, so my current dosage only equals just under 4.5ml of vodka. It makes sense that nitrate isn't plummeting when I put it that way. As I stated in my last post, I've been dosing sodium bicarbonate to bring alkalinity up. It's now at 7.6 dKh. I tested calcium tonight and it's sitting pretty at 390ppm. Salinity is a little lower at 1.025sg due to rinsing vials with tank water so much and a day of a skimmer mishap (turns out it needed to be cleaned...weird). I'm doing another 10% water change tomorrow morning after I do my daily nitrate, phosphate, and alk check. I'll take out a little less than I add to raise the salinity once the extra water evaporates. Obviously my major, minor, and trace elements will rise, but honestly I'm only concerned about alkalinity. Nitrate should be down to 24.5ppm or lower post water change while phosphate should remain unchanged for the most part. Another change I've made is adding rox carbon to my media reactor and putting it back online. I'm curious to see if the area inside the reactor will be more conducive to bacterial growth and increase nutrient reduction.

Another question I have. Since the bacteria is suspended in the water, will my clarisea remove any of it from the water column? The filter material is 20 microns.

 

[Dan_P]

The phosphate dropping was truly a head scratcher. I had to dose neophos a few days in a row to raise it to 0.07ppm. It's been steady after 3 days since my last dose. Nitrate remains stable at 27ppm +/- 0.5ppm (within test margins). I've increased dosing distilled white vinegar to 35ml and will continue to monitor for a few days before increasing it another 5ml. I have to keep in mind that vinegar is 8 times less potent than vodka, so my current dosage only equals just under 4.5ml of vodka. It makes sense that nitrate isn't plummeting when I put it that way. As I stated in my last post, I've been dosing sodium bicarbonate to bring alkalinity up. It's now at 7.6 dKh. I tested calcium tonight and it's sitting pretty at 390ppm. Salinity is a little lower at 1.025sg due to rinsing vials with tank water so much and a day of a skimmer mishap (turns out it needed to be cleaned...weird). I'm doing another 10% water change tomorrow morning after I do my daily nitrate, phosphate, and alk check. I'll take out a little less than I add to raise the salinity once the extra water evaporates. Obviously my major, minor, and trace elements will rise, but honestly I'm only concerned about alkalinity. Nitrate should be down to 24.5ppm or lower post water change while phosphate should remain unchanged for the most part. Another change I've made is adding rox carbon to my media reactor and putting it back online. I'm curious to see if the area inside the reactor will be more conducive to bacterial growth and increase nutrient reduction.

Another question I have. Since the bacteria is suspended in the water, will my clarisea remove any of it from the water column? The filter material is 20 microns.

Bacteria in the water don’t necessarily live as individuals but in clumps or on suspended particles. This makes it possible to remove bacteria by filtration. A skimmer will also remove them.

 

[Oregon Grown Reef]

Bacteria in the water don’t necessarily live as individuals but in clumps or on suspended particles. This makes it possible to remove bacteria by filtration. A skimmer will also remove them.

I knew the skimmer would remove it, but wasn't sure about the filter. Thanks again!

 

[Oregon Grown Reef]

After 3 weeks of dosing and getting up to 35ml for 50 gallons total water volume, my nitrate is coming down at a rate of 2ppm per day. My phosphate is getting consumed at a rate of 0.04ppm per day, which I was not expecting. I am now back to dosing 8ml of neophos per day to keep phosphate up. Since I don't want to bottom out phosphate, I lowered the dosage to 25ml of vinegar and will continue to test daily until I get nitrate down to 10ppm. At that point I'll lower the dosage to achieve the goal of allowing it to rise 1-2ppm per week and do biweekly water changes to keep the levels down. @Dan_P and @Randy Holmes-Farley, you've both been incredibly helpful. I wouldn't have had the confidence moving forward with this method if it weren't for you. I hope I haven't bothered you too much. My goal was to ask good questions and provide adequate details so others that may come across this thread can read it and learn something valuable.

 

[Dan_P]

After 3 weeks of dosing and getting up to 35ml for 50 gallons total water volume, my nitrate is coming down at a rate of 2ppm per day. My phosphate is getting consumed at a rate of 0.04ppm per day, which I was not expecting. I am now back to dosing 8ml of neophos per day to keep phosphate up. Since I don't want to bottom out phosphate, I lowered the dosage to 25ml of vinegar and will continue to test daily until I get nitrate down to 10ppm. At that point I'll lower the dosage to achieve the goal of allowing it to rise 1-2ppm per week and do biweekly water changes to keep the levels down. @Dan_P and @Randy Holmes-Farley, you've both been incredibly helpful. I wouldn't have had the confidence moving forward with this method if it weren't for you. I hope I haven't bothered you too much. My goal was to ask good questions and provide adequate details so others that may come across this thread can read it and learn something valuable.

Looking forwards to more of your reports of success. Others will certainly learn from your posts.

Dan

 

[Randy Holmes-Farley]

After 3 weeks of dosing and getting up to 35ml for 50 gallons total water volume, my nitrate is coming down at a rate of 2ppm per day. My phosphate is getting consumed at a rate of 0.04ppm per day, which I was not expecting.

Looking at relative consumption rates is complicated as phosphate can come on and off of rock and sand, and nitrate can be consumed by denitrification, but that ratio of 2 ppm nitrate to 0.08 ppm phosphate is not an unreasonable one to observe.

 

[Oregon Grown Reef]

Looking at relative consumption rates is complicated as phosphate can come on and off of rock and sand, and nitrate can be consumed by denitrification, but that ratio of 2 ppm nitrate to 0.08 ppm phosphate is not an unreasonable one to observe.

I'm assuming you meant 0.04 ppm of phosphate. Glad to know it doesn't sound unreasonable. If it keeps up at that rate, I'll have to get phosphate set up on a dosing pump as well.

 

[Randy Holmes-Farley]

I'm assuming you meant 0.04 ppm of phosphate. Glad to know it doesn't sound unreasonable. If it keeps up at that rate, I'll have to get phosphate set up on a dosing pump as well.

I meant the values I wrote based on this post of yours that I quoted.

“After 3 weeks of dosing and getting up to 35ml for 50 gallons total water volume, my nitrate is coming down at a rate of 2ppm per day. My phosphate is getting consumed at a rate of 0.04ppm per day, which I was not expecting.”

 

[Oregon Grown Reef]

Is adding trace elements to vinegar a possibility without them precipitating out?

 

[Randy Holmes-Farley]

Is adding trace elements to vinegar a possibility without them precipitating out?

That may depend on the forms of trace elements. It may be worth trying and seeing if it stays clear.

 

[Oregon Grown Reef]

That may depend on the forms of trace elements. It may be worth trying and seeing if it stays clear.

I have Tropic Marin A- and K+. From what I understand, I can't put both in as they'd interfere with each other. I could be wrong about that. I would rather add K+ as I've read iron can get depleted from carbon dosing, but I could be wrong about that too. Any pointers?

 

[Randy Holmes-Farley]

I have Tropic Marin A- and K+. From what I understand, I can't put both in as they'd interfere with each other. I could be wrong about that. I would rather add K+ as I've read iron can get depleted from carbon dosing, but I could be wrong about that too. Any pointers?

I think it is worth a try. Iron is more of an issue with solubility at high pH.