Potassium nitrate (Spectracide stump remover) dosing steps

[Randy Holmes-Farley Verified Community Expert]

Do you use a skimmer? The algae could be due to bacteria imbalance and not phos

What sort of bacterial imbalance do you believe leads to algae growth?

 

[redwingrob40]

Do you use a skimmer? The algae could be due to bacteria imbalance and not phos

Yes I do run a skimmer, its a aquamaxx cone CO2. Are you thinking too much or too little bacteria? I would think that too much could be an issue if it were sucking up the nitrates, but I could be wrong...

 

[Jonathan Presseau]

From what I understand we have tons of different bacteria in our systems. I started dosing MicroBacter7 about 10 days ago to combat with cyano algae growing on the sand bed and my Zoas. The tank is a zoa garden with several fish. I feed both the Zoas and fish quite heavily. My nitrates range from 5-10ppm by dosing and phos remains very low. I just bought a new custom sump to fit a coral box d300 skimmer - I have not used a skimmer on this tank yet. I think the combo of no skimmer and certain bacteria dominating the system has led to the cyano problem.

 

[Randy Holmes-Farley Verified Community Expert]

I can readily accept bacterial levels and types impact cyano, because it is another type of bacteria competing for some of the same limiting resources (including organics to consume).

I'm not sure I'd extend that to algae, which generally do not consume organics.

 

[Jonathan Presseau]

Interesting. Is cyano not a type of algae?

 

[chefjpaul]

Interesting. Is cyano not a type of algae?

Cyano(bacteria).

 

[Jonathan Presseau]

Well in that case forget the algae part of my post above. The skimmer is required due to heavy feeding for me and the microbacter7 is for the cyano.

 

[jumplittlechloe]

Still dealing with burnt tips on all SPS and now have cyano. Nitrates are holding at 2.5ppm. Things are not well and I don't know why.

 

[Jonathan Presseau]

I suggest you try what I am doing. microbacter7 dosing

 

[jumplittlechloe]

I suggest you try what I am doing. microbacter7 dosing

I am already dosing products from the Aquaforest line with includes a bacteria source. I think there are probably four reasons for burnt tips on SPS:

1. Quick increase of K+ (potassium)
2. Quick drop in PO4
3. High KH
4. toxins leach into the system

My KH is in line 7.4dkh and I don't think there are any toxins. I think that dosing potassium nitrate has caused 1 or 2. Visually I can see PO4 has changed (less algae on glass and rock). I do not have a K test so I am not sure what that number may be.

Could the potential drop in PO4 lead to the cyano outbreak?

 

[Jonathan Presseau]

Interesting. I have not tried dosing this yet in my mixed reef - only zoa garden. I also have the cyano issue. My phos levels are also quite low and I can also agree I clean the glass less. I keep my alk at 8.5-9. I think you may be on to something, but I also do not have a potassium test.

It is hard for me to tell yet if the dosing is actually helping the Zoas. They have been through hell and back in this tank. I have had many issues that a 1 year old tank would have over the months. I have also switched salts, lights, flow and filtration. I've had issues with amphipods, coloniata snails, cyano, too much light, bad salt mix, you name it. Finally though they are looking better and coloring back up. I would say it has a lot to do with the lighting, but ridding of the cyano is certainly helping. If dosing potassium nitrate led to the cyano maybe I am fighting my own battle by then needing to dose microbacter7.

 

[The-Russ]

I stopped dosing Nitrates a few days ago and my levels are still the same as when I quit dosing.

Shouldn't they fallback to 0?

 

[jent]

I would think if your nitrate is not falling, you are likely constrained by something else, ie carbon or phosphate.

 

[The-Russ]

I would think if your nitrate is not falling, you are likely constrained by something else, ie carbon or phosphate.

What do you mean? I know I have a small phosphate issue. The test shows 0, but I do have some algae. That is why I dosed the nitrate to begin with. Both NO3 and PO4 were zero.

I was dosing carbon and quit for a bit because of cyano. I started back with .1ml Vodka per 25gal the other day.

I am open to suggestions.

 

[jent]

As I understand it, carbon, nitrogen, and phosphate are what's needed for the bacterial processes. Those processes will continue to get more intense until one of those become the limiting factor. You obviously can get too much bacteria, which would be seen as cloudy milky water, etc.

So if your nitrate is not going down, one of those other two have to be the limiting factor. Since you said you have detectable nitrate, and you also said you stopped dosing carbon it sounds like carbon could likely be the limiting factor now.

In my tank it's super high flow, there is no way cyano would be able to hold on to anything. So I am able to (and trying to) turn this process up pretty high as a way to keep my phosphate down. My experience in this so far has shown that for me I need to dose both carbon and nitrate in order to be able to consume phosphate at levels which they are being added into the tank.

If you want to lower your nitrate and phosphate, I would resume your carbon dosing, and deal with the other issues in ways that don't involve reducing your carbon. If you can't keep your carbon source higher, your going to need to use other methods for reducing your nitrate and phosphate (water changes, GFO, nitrate reactor, algae scrubber, etc).

 

[Jonathan Presseau]

When you say turn this process up pretty high can you elaborate please?

 

[jent]

I have been dosing nitrate, and then as my nitrate became detectable I increased my carbon to try and remove phosphate. At my current rates I have been running with phosphate undetectable for about a week. Not my long term plan, but trying to get some algae under control.

 

[Randy Holmes-Farley Verified Community Expert]

My experience in this so far has shown that for me I need to dose both carbon and nitrate in order to be able to consume phosphate at levels which they are being added into the tank.

That is pretty common, since organic carbon dosing is typically overbalanced toward nitrate export. So to reduce phosphate before nitrate runs out, folks either need to dose a nitrogen source (such as nitrate or amino acids), or export some phosphate some other way.

 

[jent]

Interesting...I just tested my potassium (red sea), and it was super low. I am using sodium nitrate for my nitrate dosing. Would it make sense that my potassium usage would be increased from my increased carbon dosing? Maybe potassium nitrate makes more sense as a nitrate source.

 

[Jonathan Presseau]

This thread is great