creepingdeath086
New member
are there any sort of fertilizers or substances that are safe to use in a macro algae tank to speed their growth?
enhancing macroalgae growth
- Thread starter creepingdeath086
- Start date
Triterium
New member
I use fertilizer from www.florida-aqua-farms.com If you have a high bioload, the plant fuel works well. I am starting to use micro algae grow on my planted tank. It is "plant fuel" plus nitrates and phosphates. These fertilizers were designed for algaes.
Plantbrain
Active member
Generally KNO3 works well, PO4 is not needed in high amounts and cause diatom blooms generally. Dosing a 1/8 teaspoon in 80- liters of KNO3 adds about 5 ppm of NO3.
Done once a week or two, generally tops off the need for the macros.
Traces are generally present in enough concentrations to supply the nutrients, Fe can be added if desired.
Alk and Ca are the other main things that many macro's use a fair amount of. Keep them high.
Regards,
Tom Barr
Done once a week or two, generally tops off the need for the macros.
Traces are generally present in enough concentrations to supply the nutrients, Fe can be added if desired.
Alk and Ca are the other main things that many macro's use a fair amount of. Keep them high.
Regards,
Tom Barr
creepingdeath086
New member
micro algae grow may add too much of a good thing, if my memory serves me correct KN03 is potassium nitrate? where would i go about getting that? or is it in something that i already have somewhere? also no one has mentioned c02..does that work on a saltwater tank? thanks
Samala
New member
KNO3 = potassium nitrate, you are correct. 
There are a couple of DIY sources like http://www.gregwatson.com in the PMDD shop. Some people try a stump remover found in hardware stores but I wouldnt even dare. Easiest sources are freshwater directed things like Seachem's Flourish Nitrogen.
Is this a macro only tank?
As far as CO2, when I tried it on seagrasses I did see a little bit of growth improvement, but nothing exciting. There is a published paper on CO2 supplementation with eelgrass (Zostera marina). They used lots of CO2 to bring saltwater pH to high 6's and pretty much tripled the photosynthetic rate of the plants. But, that's not going to be true across the board.
I didnt push so much CO2 to drop the pH lower than 7.6 from 8.2.. so perhaps I didnt use enough for the plants to increase growth much. Right now I'm using Seachem's Flourish Excel and that has seemed to improve the uptake of iron in the tank and the algaes on the glass take a little longer to grow. I also 'think' that they are uptaking the carbon from the mix, which wouldn't be available to pest algaes (and likely macro algaes).
Last thought - I'm quite sure that the macroalgae's do not need a CO2 source to grow. I under stand they'll take their carbon by stripping it from the alkalinity in the saltwater, usually off the CaCO3 molecule. (Tom please do correct me if I've got this all messed up.) So, if your alk levels are good.. the algae's should be good to go. Watch your calcium levels also if you have a lot of plants in the tanks that are calcified - particularly Halimeda, mermaid's brush, etc.
>Sarah
There are a couple of DIY sources like http://www.gregwatson.com in the PMDD shop. Some people try a stump remover found in hardware stores but I wouldnt even dare. Easiest sources are freshwater directed things like Seachem's Flourish Nitrogen. Is this a macro only tank?
As far as CO2, when I tried it on seagrasses I did see a little bit of growth improvement, but nothing exciting. There is a published paper on CO2 supplementation with eelgrass (Zostera marina). They used lots of CO2 to bring saltwater pH to high 6's and pretty much tripled the photosynthetic rate of the plants. But, that's not going to be true across the board.
I didnt push so much CO2 to drop the pH lower than 7.6 from 8.2.. so perhaps I didnt use enough for the plants to increase growth much. Right now I'm using Seachem's Flourish Excel and that has seemed to improve the uptake of iron in the tank and the algaes on the glass take a little longer to grow. I also 'think' that they are uptaking the carbon from the mix, which wouldn't be available to pest algaes (and likely macro algaes).
Last thought - I'm quite sure that the macroalgae's do not need a CO2 source to grow. I under stand they'll take their carbon by stripping it from the alkalinity in the saltwater, usually off the CaCO3 molecule. (Tom please do correct me if I've got this all messed up.) So, if your alk levels are good.. the algae's should be good to go. Watch your calcium levels also if you have a lot of plants in the tanks that are calcified - particularly Halimeda, mermaid's brush, etc.
>Sarah
Triterium
New member
creepingdeath086 said:
What information are you basing this statement on?
Here is a description of "plant fuel"
Complete soluble, stable source of supplemental trace metals and vitamins. Principally formulated for commercial aquaculture to enhance growth and color of large (macro) freshwater and saltwater plants and algae. This formula has been used in Florida Aqua Farmââ"šÂ¬Ã¢"žÂ¢s plant division for over 17 years. Primary nutrients, nitrate and phosphate, are not present in Plant Fuel . Formulated for use in aquaria and ponds that have established populations of fish and/or invertebrates that are being fed. Metabolism of waste products and excess food normally provide suitable levels of nitrate and phosphate. If you intend to grow only plants we suggest our full strength formula Plant Fuel Too. Both Plant Fuelââ"šÂ¬Ã¢"žÂ¢s are enriched with chelated iron, iodide and other essential aquatic trace metals and vitamins including B12, biotin thiamin and others.
I asked them about the "full strengh formula" and they said it is the micro algae grow.
Plantbrain
Active member
You can use Grant's brand or Cooke's brand stump remover for KNO3.
Anything that says you need to light a fire etc and has a sharp bleach like smell, do not use for FW or Marine.
The other's are almost always KNO3 and fairly close to 100% pure.
Regards,
Tom Barr
3rd annual plant fest! Key Largo FL, July 12-14th.
Collect, identify and see all your favorite marine plants in their natural environment!!
www.BarrReport.com
Anything that says you need to light a fire etc and has a sharp bleach like smell, do not use for FW or Marine.
The other's are almost always KNO3 and fairly close to 100% pure.
Regards,
Tom Barr
3rd annual plant fest! Key Largo FL, July 12-14th.
Collect, identify and see all your favorite marine plants in their natural environment!!
www.BarrReport.com
creepingdeath086
New member
thank you all for youyr replys i will have to try out the florida aqua farms stuff, and see how it does, it looks like the best bet here.
Plantbrain
Active member
T-
CD wants to grow macro algae, not micro algae.
They have different needs and are in a different niche.
Either way, FAF does NOT add NO3/PO4 to their mix, so what is left as far as essential nutrients for algae or plants?
Traces and Ca/SO4, Mg etc, stuff that's normally present in high amounts in Salt mixes anyway...................
This is not brain surgery here nor is FAF 17 years of using a trace really that proven anymore than any other product.
FAF and other makers of ferts for algae generally assume the NO3/NH4 and PO4 will come from the fish/critter waste in enough supply for the micro algae.
That's fine and all for micro algae, they have very low demand for N and P.
Macro algae have a great need/demand for these two nutrients.
That's why adding KNO3 will increase the growth rates and why you see Caulerpa melting after a peroid of agressive growth after the NO3 has bottomed out.
If you add enough NO3 to maintain the levels, then the Caulerpa continues to grow and does not melt.
Macro's also have a great demand for Ca++ and alkalinity since many have CaCO3 frames like corals except macros grow even faster and remove these from the water column.
You can buy traces most anywhere.
If the goal is to grow micro algae in a culture, then a number of prepared culturing methods can be done and are available in the literature.
Regards,
Tom Barr
CD wants to grow macro algae, not micro algae.
They have different needs and are in a different niche.
Either way, FAF does NOT add NO3/PO4 to their mix, so what is left as far as essential nutrients for algae or plants?
Traces and Ca/SO4, Mg etc, stuff that's normally present in high amounts in Salt mixes anyway...................
This is not brain surgery here nor is FAF 17 years of using a trace really that proven anymore than any other product.
FAF and other makers of ferts for algae generally assume the NO3/NH4 and PO4 will come from the fish/critter waste in enough supply for the micro algae.
That's fine and all for micro algae, they have very low demand for N and P.
Macro algae have a great need/demand for these two nutrients.
That's why adding KNO3 will increase the growth rates and why you see Caulerpa melting after a peroid of agressive growth after the NO3 has bottomed out.
If you add enough NO3 to maintain the levels, then the Caulerpa continues to grow and does not melt.
Macro's also have a great demand for Ca++ and alkalinity since many have CaCO3 frames like corals except macros grow even faster and remove these from the water column.
You can buy traces most anywhere.
If the goal is to grow micro algae in a culture, then a number of prepared culturing methods can be done and are available in the literature.
Regards,
Tom Barr
Plantbrain
Active member
Here's the quote:
So they tell you it's a trace.........
That pretty much says what I said.
It lacks NO3/PO4.
So if you do not have enough NO3 in your present bioload, then you need to add more.
Fish food does not have enough N or P in decent ratios, most are N heavy, P light.
The goal for this product is to reduce the NO3/PO4.
Whjat happens and folks have issues with is running their NO3/PO4 down to zero, that favors cyanos and microalgae, not plants and macro algae. The larger plants just sit there, stop growing or melt and produce gametes and end up being great substrates for the smaller epiphytes.
It's like mice and elephants, both eat plants, but one needs far less and can reproduce much faster, the other needs far more and reproduces slowly but grows much larger and faster relatively.
Here they state the obvious again, if you have high plant density, you will need more nutrients.
But what they do not tell you...............you also will be limited as far as macro nutrients, N and P.
You add everything else except N and P and they will bottom out in the tank.
Some feel they can simply add more fish/fish food /critters etc.
Well, that works up to a point.
Youy over load any tank with fish waste and you will get algae no matter how you fertilize. This is due to higher levels of NH4, not NO3.
You can add both and see the result.
I can add 5ppm of NO3 and then see the response then try 0.5ppm of NH4 and bam!, microalgae everywhere.
There are many studies on the size of algae and the nutional needs and competition. The uptake rates for tiny algae are extreemely good at very very low nutrient levels while the larger macro algae need more concentration.
That's why tiny algae are found out in the low nutrients regions and the macros like kelps and seagrasses are found in nutrient rich areas close to shore.
We do not find many plants in Lake Tahoe (yet), but we find lots in the Sac River delta. We also high production in the rich waters off CA and very low production in nutrient poor regions such as central gyres of the ocean.
Regards,
Tom Barr
So they tell you it's a trace.........
That pretty much says what I said.
It lacks NO3/PO4.
So if you do not have enough NO3 in your present bioload, then you need to add more.
Fish food does not have enough N or P in decent ratios, most are N heavy, P light.
The goal for this product is to reduce the NO3/PO4.
Whjat happens and folks have issues with is running their NO3/PO4 down to zero, that favors cyanos and microalgae, not plants and macro algae. The larger plants just sit there, stop growing or melt and produce gametes and end up being great substrates for the smaller epiphytes.
It's like mice and elephants, both eat plants, but one needs far less and can reproduce much faster, the other needs far more and reproduces slowly but grows much larger and faster relatively.
Here they state the obvious again, if you have high plant density, you will need more nutrients.
But what they do not tell you...............you also will be limited as far as macro nutrients, N and P.
You add everything else except N and P and they will bottom out in the tank.
Some feel they can simply add more fish/fish food /critters etc.
Well, that works up to a point.
Youy over load any tank with fish waste and you will get algae no matter how you fertilize. This is due to higher levels of NH4, not NO3.
You can add both and see the result.
I can add 5ppm of NO3 and then see the response then try 0.5ppm of NH4 and bam!, microalgae everywhere.
There are many studies on the size of algae and the nutional needs and competition. The uptake rates for tiny algae are extreemely good at very very low nutrient levels while the larger macro algae need more concentration.
That's why tiny algae are found out in the low nutrients regions and the macros like kelps and seagrasses are found in nutrient rich areas close to shore.
We do not find many plants in Lake Tahoe (yet), but we find lots in the Sac River delta. We also high production in the rich waters off CA and very low production in nutrient poor regions such as central gyres of the ocean.
Regards,
Tom Barr
Plantbrain
Active member
Well if you use the KNO3/KH2PO4 you can control the ratio of N and P easily and tailor it to your tank's needs and loading of both N and P based of the fish load/feeding.
So........
Most commercial products are dilute and weak.
Regards,
Tom Barr
So........
Most commercial products are dilute and weak.
Regards,
Tom Barr
Samala
New member
Gonna jump in here - Tom is advocating splitting up your macro nutrients because its going to be easier on you in the long run... if you're running a macroalgae heavy tank. Most reefers use the macro's only to try to deplete PO4 or NO3 levels in their tanks.. but if the purpose is to grow a lot of macroalgae, chances are that you will eventually run out of nitrate and phosphate for them to grow upon. I know in my tank I need to dose nitrate every three days or it goes to zero. If I dont dose I get a diatom bloom and the green algae that likes the glass grows aggressively. Add a little nitrate, problem usually solved. But I have a lot of plants, and practically no bioload (unless you count two grass shrimp that are fed maybe once a week).
If you get to zero, the trace mixes wont help much.. and the mixes that are effectively all-in-one dont give you a lot of control. I would hope in a commercial mix tailored to microalgae's it would be close to what you need.. but if its favoring a microalgae profile, may be hard to keep up with. All tanks will probably run a little different, so it honestly is easier on you to separate them out and add individually. It very well may work beautifully in your tank, which is why I've said before to just jump in and try it out. If you get microalgae out of control, switch to individual dosing.
IMO, the greatest thing about individual dosing and mixing your own macronutrient brews is that you know exactly how much you're adding and can bring up your ppm levels to where you want them without a lot of guessing and testing.
For CD, if the idea is just to grow a few macroalgaes, the trace may well be enough and adding phosphate and nitrate only a secondary consideration if he has a decent bioload and not alot of things competing with it. Thats with a light plant component in the tank.
Speaking of competition, do we think that the live rock component of a typical reef competes greatly with the macroalgae's in scavanging NO3 from a system? Or do the plants/algaes tend to one-up the live rock bacteria before they can grab that nitrate away?
As always, feel free to teach me something if this is wrong.
>Sarah
If you get to zero, the trace mixes wont help much.. and the mixes that are effectively all-in-one dont give you a lot of control. I would hope in a commercial mix tailored to microalgae's it would be close to what you need.. but if its favoring a microalgae profile, may be hard to keep up with. All tanks will probably run a little different, so it honestly is easier on you to separate them out and add individually. It very well may work beautifully in your tank, which is why I've said before to just jump in and try it out. If you get microalgae out of control, switch to individual dosing.
IMO, the greatest thing about individual dosing and mixing your own macronutrient brews is that you know exactly how much you're adding and can bring up your ppm levels to where you want them without a lot of guessing and testing.
For CD, if the idea is just to grow a few macroalgaes, the trace may well be enough and adding phosphate and nitrate only a secondary consideration if he has a decent bioload and not alot of things competing with it. Thats with a light plant component in the tank.
Speaking of competition, do we think that the live rock component of a typical reef competes greatly with the macroalgae's in scavanging NO3 from a system? Or do the plants/algaes tend to one-up the live rock bacteria before they can grab that nitrate away?
As always, feel free to teach me something if this is wrong.
>Sarah
Triterium
New member
Thank you. 
I think the all-in-one fertilizer may be good for smaller tanks where water changes are a lot easier. And also where the person doesn't want to spend the time adding 5 different additives and testing constantly. I think the buildup of certain nutrients over time would definitely create problems when using the micro algae grow. Frequent water changes should take care of that however.
Ideally, every nutrient would be added separately and would be accompanied with frequent testing of all major and minor nutrients. This, however, is probably not necessary and the testing of several major nutrient levels should suffice.
The addition of traces over extended periods may increase their concentrations to problematic levels. If testing of these nutrients is not done, frequent water changes may prevent a buildup. But then again, if you're doing lots of water changes, you may not need to add the traces.
Ok, so here is what im thinking ill do with my tank....
Add nitrate and test level
Add phosphate and test level
Add iron and test level
Test and maintain calcium, alkalinity, and pH
Add traces (maybe at 1/2 the recommended dosage)
How does that sound Tom?
I think the all-in-one fertilizer may be good for smaller tanks where water changes are a lot easier. And also where the person doesn't want to spend the time adding 5 different additives and testing constantly. I think the buildup of certain nutrients over time would definitely create problems when using the micro algae grow. Frequent water changes should take care of that however.
Ideally, every nutrient would be added separately and would be accompanied with frequent testing of all major and minor nutrients. This, however, is probably not necessary and the testing of several major nutrient levels should suffice.
The addition of traces over extended periods may increase their concentrations to problematic levels. If testing of these nutrients is not done, frequent water changes may prevent a buildup. But then again, if you're doing lots of water changes, you may not need to add the traces.
Ok, so here is what im thinking ill do with my tank....
Add nitrate and test level
Add phosphate and test level
Add iron and test level
Test and maintain calcium, alkalinity, and pH
Add traces (maybe at 1/2 the recommended dosage)
How does that sound Tom?
Samala
New member
I've been wondering about magnesium myself, was adding a smidge every week or so just prophylactically... but I have no idea what true needs are.
Usually with traces the idea is to use a mix that includes iron, and then test for iron, and assume that that is a good reference for all the other traces in the mix.
Ca/alk and pH.. all good to test for I'm finding out. I was hoping without calcified species in my tank I wouldnt have an issue.. but the pH has gone a little crazy with the photosynthetic rates being what they are.
>Sarah
Its so funny that you are mentioning frequent water changes becuase that is, I think, basically Tom's method in freshwater. Dose everything, dont worry about buildup because you'll do water changes. (Are people cringing as they read this..??)
Usually with traces the idea is to use a mix that includes iron, and then test for iron, and assume that that is a good reference for all the other traces in the mix.
Ca/alk and pH.. all good to test for I'm finding out. I was hoping without calcified species in my tank I wouldnt have an issue.. but the pH has gone a little crazy with the photosynthetic rates being what they are.
>Sarah
Its so funny that you are mentioning frequent water changes becuase that is, I think, basically Tom's method in freshwater. Dose everything, dont worry about buildup because you'll do water changes. (Are people cringing as they read this..??)
Samala
New member
I was considering using CaNO3 myself... but worried about my calcium levels getting outta control. Now that I got test kits maybe I'll try that this week.
The plants do need some potassium.. dosing with KNO3 is a nice way to meet both requirements usually without dosing another separate mix like KCl (often sold as diabetic salt).
But... maybe in a marine environment using NaNO3 would be better. This IS what they use in f/2 guillards medium instead of KNO3. No reason is really given for why. But, that was also intended first for growing microalgae.. so perhaps microalgae's dont really need potassium.
I'll try looking through my notes for potassium req's in plants and algeas... maybe something will come up.
PS: if your new avatar isnt seagrass, what is it? I miss the old one..
>Sarah
The plants do need some potassium.. dosing with KNO3 is a nice way to meet both requirements usually without dosing another separate mix like KCl (often sold as diabetic salt).
But... maybe in a marine environment using NaNO3 would be better. This IS what they use in f/2 guillards medium instead of KNO3. No reason is really given for why. But, that was also intended first for growing microalgae.. so perhaps microalgae's dont really need potassium.
I'll try looking through my notes for potassium req's in plants and algeas... maybe something will come up.
PS: if your new avatar isnt seagrass, what is it? I miss the old one..
>Sarah
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