Well...
quite a number of things here.....
to begin with, phosphate testkits are amongst the most difficult to discern an accurate reading from...you gave a very specific reading with a so so testkit.--better than the Salifert but not all that great--your readings could be wrong.
you are using 500ml of Rowa...mindboggling...if you read through the many threads on the use of Rowa you would find that that is way way too much...in two reactors no less..did you use rowa in your other tanks? how often do you change it out? whats the flow rate? why are you using rowa in the first place? did you test the water in the main and compare it to the output from the p reactors? did you test the RO water? did you test the mixed salt water?
if your tank is really only 6 weeks new then messing with the natural cycling period with a chemical crutch isn't going to do the trick...
it seems to me almost impossible to have that kind of reading with so much Rowa...your messing with PO4 in a major way ..it could even become saturated and emit phosphates back into the system given enough time...
what is your nitrate reading?
is the LR recently purchased or did you take it from another tank? if it's new, that's probably the problem. can you set up a small prop tank for your corals for a while?if so then cut the photoperiod at least to half to help the algae problem and let the tank stabilize and stop using the rowa...
no fish in tank--not an issue--no food in tank, not an issue
why are you putting DT's in the tank anyway? not to open a can of worms here but with your algae problem it's a good idea not to......
the skimmer efficiency effects PO4 but doesn't directly remove it..if its working at all the the problem lies elsewhere.
there are so many sources of PO4 but no major ones that haven't been covered already here--apart form air contaminants--that seem at all likely....
try switching salts, do more water changes, add more flow is what some would recommend, at least to combat the algae....
if Randy Holmes-Farley were to respond to this thread he would probably conclude by telling you to check your testkits...
do you know your ORP, BTW? just curious...
needless to say a fuge would be a great addition for the long term...
let us know how things develop and good luck.
