Go ahead and lower the pH - it's not that much of an acid. You want the pH around 7.0 -- the HEDP can't pick up the iron if the pH is high.
About the cloudiness -- I don't know what's happening. How much did you put in? An overdose of HEDP can cause cloudiness, but I've never seen a company label an HEDP product at doses high enough to cause that.
I'll call Kem-Tek, to see if I can find out if anything ELSE is in that product. You go ahead and lower the pH, and keep filtering.
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