PO4 Help


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Jul 25, 2017
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Thank you. I have been testing twice a day for two weeks and changing GFO every other day. Over this time the PO4 has fluctuated between .13 and .23. It has gone up and down but no trend. Nothing else has changed. I always thought GFO would strip PO4 quickly, but it doesn’t seem to be doing much of anything.
Flow through the GFO will have a significant impact on its ability to remove PO4.

You don’t need to test so often, maybe twice a week at the most until you get it to a level you are happy with.

If you are unsure about your test results, you could always send out an ICP test. I would recommend testing your water yourself at the same time you take the sample for the ICP test so you have an accurate reference to compare the results with.
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