Phosphate - Phosphorus??

TonyN

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Mar 31, 2004
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Hi,
I'm new here, Just registered. Looks like a great forum. Anyway, I read the sticky on fertilizers and it helps a lot. However there is something I dont understand. When you talk about phosphates, is this the same as phosphorus (as in Flourish Phosphorus)? Right now I'm fighting a phosphate problem (off the chart according to the SeaTest Kit). Therefore I assume I wouldn't want to add any Phosphorus. Is this correct?
Also my Nitrates read 20 to 40, so I think I would not want to add any Nitrogen. Right or wrong?
I would appreciate any help you could give me on this,

Thanks
 
Welcome to the forum!!
You can probably put a big dent in your Nitrate/Phosphate problem with a series of large water changes. They are one of the most effective means of renewing your water.
You want to keep the N between 5ppm and 10ppm and the P between .50 and 1.0. This should be balanced with K and Trace elements. Balance of nutrients and water changes are the keys to a healthy tank.
There are many knowledgeable people haunting this forum who can help so don't hesitate to ask questions.
It would be of enormous help if you could compile your tank's vital statistics and put them in the Signature section of your posts for reference, so that you won't have to repeat them every time someone asks you how much light you have and what type of filtration or substrate do you use, etc. Then, every time you post, all that info. will be available at the end of the post.

Len
 
Len,
Thanks for your welcome. I've been doing a lot of water changes, but it doesn't seem to help. Right now I'm using Seachem Phosguard.
Anyway, I still need to know if the phosphate I've got is the same thing as when you add Flourish Phosphorus.
Also are nitrates the same thing as when you add Flourish Nitrogen,

Thanks
 
Phosphate is what the plants use and you use for that matter, seldom is Phosphorus ever free in biochemical reactions and not for long. PO4= phosphate P= phosphorus.

While you can have high PO4 levels, you might not have any PO4 that is available for plants, it might be mainly organic bound PO4.
If you don't do many/enough weater changes, have too high a fish load, over feed a lot, use a PO4 based acid "buffer" to lower pH then you will have problems generally.

Large frequent water changes tend to keeop the levels low. Adding inorganic sources of PO4, NO3 etc is a good idea as these are most available to the plants.

Periphyton and algae that bother you can use organic forms of PO4 that the plants cannot use. They also can live on far less PO4 than any can possibly live on.

Removing the PO4 does not prevent algae or limit it when you have plants.

If you do this critically, you will find this to be true. Plants will slow their growth down when PO4 limited.

But the needs of the plants are still far greater than the PO4 needs of the algae.

So you need to ask the question: is your goal to grow the plants?

Focus on their needs, not on limiting nutrient for algal control. You will chase your tail for a long time till you figure this out.

Regards,
Tom Barr
 
Ok - now I'm getting confused. Right now I have about 5 mg/L
phosphates. I'm using seachem phosguard to get it down.
I've been doing water changes, 25 per cent every week. I have a 20 Gallon tank, heavily planted, with a lot of fish (probably overstocked). I'm using the whole line of Flourish nutrients, except Phosphorus and Nitrogen. I'm not using any Phosphate buffers, or any other chemicals other than what I've listed.
I'm injecting CO2 at about 30 Bubbles per minute, and my CO2 level is about 18 ppm. pH 6.8, kH about 3.5.
So are you saying I should leave the Phosphates alone and just live with the algae? My goal is definitely to grow the plants, but my algae is to the point where I have to clean the glass every other day to keep it clean. I dont mind doing that if thats what it takes, but that much algae seems excessive.
What do you suggest?
Thanks
 
>>Ok - now I'm getting confused. Right now I have about 5 mg/L
phosphates. I'm using seachem phosguard to get it down.

Not sure what this is, but I'm pretty sure it's not a nuclear reactor, so the most it can do is tie up your phosphates (so it's unavailable to algae/plants), but how in the world would it actually make them go away?

>>I've been doing water changes, 25 per cent every week.

If you really want the phosphates to go down, do 60-70% water changes every other day for a few days, then weekly 50%. Crypts might melt, but they always do anyway. Weekly 25% is nothing.

>> I have a 20 Gallon tank, heavily planted, with a lot of fish (probably overstocked). I'm using the whole line of Flourish nutrients, except Phosphorus and Nitrogen. I'm not using any Phosphate buffers, or any other chemicals other than what I've listed.

Your nitrates are good as they are. If they ever go to 0, then you'll need to dose.

>> I'm injecting CO2 at about 30 Bubbles per minute, and my CO2 level is about 18 ppm. pH 6.8, kH about 3.5.

That's about perfect, wish I could keep mine like that all the time. Is yours stable?

So, do lots of large water changes and see if it goes down. How's your tap water?
 
Tony -
What is your wattage?
How long has this tank been set up?
What types of fish and how many?
Are you injecting with DIY CO2 or pressurized? If pressurized try to pump it up to 25 - 30ppm.
What type of algae are we dealing with?
Does the whole line of Flourish products include K?
I think what Tom is saying is that limiting a particular element, in this case P, is not the answer. At least not through the use of Phosguard. Something is out of balance. You just have to figure out what it is.
A large fish load can create a high N level. Either P in the water supply or over feeding can create an excess of Phosphates. If your tap water has little or no P in it, larger water changes will alleviate this problem. I would suggest after checking the water supply for P, doing a series of large water changes of 50%.
Do one every other day. This will bring the P level down.
But you have to figure out what is causing the imbalance and correct it. You don't want to eliminate it entirely. Just to balance it with the others.
The water changes will also bring the N level down.

EDIT: Just noticed that Starry suggested many of the same things I suggest above. Sorry for the repetition.....but we are suggesting them because they work.
Please answer my first few questions so that we can get a better handle on your tank.

Len
 
Last edited:
Ok - To answer some of your questions:

65w 50/50 Coralife Aqualight
Tank has been set up for a couple years, but I only got the Aqualight and started seriously trying to grow plants about a month ago.
I have about 20 assorted platies, mollies, tetras, 3 corys, one dwarf gourami, and a couple little frogs.
Im using two of the Hagen Plantgrow systems, and getting a total of about 30 Bubble a minute.
I dont know what kind of algae this is. All I can tell you is that its green.
I've got one big Amazon Sword. A lot of Wisteria. Some anubias, a couple Ludwigia, some Cabomba, and a couple banana plants, and some java moss and java ferns.
All of the plants seem to be doing well except the Sword which is getting brown spots and a little algae on it.
The Flourish line is: Flourish, Flourish Iron, Flourish Potassium, Flourish Trace, and Flourish Excel (Carbon). I havent used the Flourish Phosphorus, or the Flourish Nitrogen yet, but I'm wondering if I should be.
pH 6.8, kH 4, CO2 about 14 today.
I guess that about tells the whole picture. I'm going to start doing those big time water changes tomorrow, like you've all suggested.
Any other suggestions? I really appreciate all the interest you guys are showing. It's nice to have a place to go for help.
Thanks
 
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