PO4 addition required ??

[nbk3]

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On 8/11/2003 3:39:57 PM

@ nbk3 :

How in the world can you dose something if you not know how much is in the water already ??

I analyse []

[nbk3]

Update :

Hmmm.... i dropped some (just a teeny weeny bit cos i know PO4 is a dangerous element [] )into my surface skimmer at about 3pm , it was when i just got back from crawford lane . Its now 10pm , and i do see my plants bubbling but its rather sparsely so i assume it could be that in the 6 hours or so , something else got depleted [] which , that will be another problem to analyse later []

and i still could'nt get that damn shrimp out

[nbk3]

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On 8/11/2003 4:13:58 PM

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On 8/11/2003 2:55:03 PM

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On 8/11/2003 11:44:37 AM

Actually, phosphate causing algae theory no longer hold.

I have had >20ppm of PO4 without algae problem. You can use the Tom Barr's estimative method.

I do "blind" PO4 doing too. I dose about 1ppm of PO4 each week.

BC
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BC,

Isn't high PO4 level (>10ppm) lethal to fishes and shrimps?
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No. Livestock don't care too much about PO4 in the ppm level.

BC

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Algae does []

[PeterGwee]

BClee is right about the PO4..it is not the issue when all the nutrients like K, traces, CO2 and NO3 are in good range. The issue is with your high bioload. Algae loves N and P but so does plants...you cannot limit algae!!!!!

[vinz]

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On 8/11/2003 9:55:42 PM

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On 8/11/2003 4:04:03 PM

Hmmm... NBK3, how often do you dose your trace elements? If you only dose after water change, of weekly, they might run out before the next dose.

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i often dose it after water changes , and i'm starting to believe it aint enuff , although its just a small 2ft tank []
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Ok, seems like PO4 is one cause. Now what you can do is to split your trace doses to 2 or 3 times a week. Usually the one after a wate change would be bigger. Say, you are supposed to dose 50ml... you can split it to 30-10-10, 20-15-15 or 30-20. I think you can increase you trace dosage a little.

[Plantbrain]

If you have algae issues, go down the list,
CO2? Check
NO3? Check
K+?Check
Traces? Check
Then PO4? Check

Make sure you have one in a good range before proceeding to the next nutrient.

If the other nutrients are in a good range, then adding PO4 will not cause algae in a fully planted tank.

If you have too many fish/critters ina tank, the excess NH4 cannot be consumed and is easy "food" for the algae, it's not the PO4 that's the issue.
This issue can also be found in nature in shallow plant infested lakes in sub and tropical regions. Adding PO4 increases plants, not the algae.

Trying to limit the algae through PO4 only hurts the plant growth more, they need far more PO4 than the algae for growth and maintenace. Algae need less than any of your test kits can possibly measure.

Regards,
Tom Barr