I think the problem is that either your liverock or that damned piece of wood is holding phosphate.
So, as you have been adding NSW with phosphate levels of 0.03, the phosphate has been accumulating in your tank (in the liverock or that damned wood).
So, now that you are using phosphate remover, the tests are showing 0.06, but that's only the phosphate free in the water. It doesn't tell you how much you have stored in the tank.
This is why when even after a 50% water change you still read high phosphates because the phosphates stored in your tank leach out when you add NSW.
Best to keep up the phosphate removal for some time and don't think that just because the meter gave you a low reading that you can now stop removing phosphate.
I suggest using the macro algae, but remember you have to keep culling the algae and removing it from your system. If you use a macro algae your fish eat, the procedure is pointless as the fish will consume the algae and return the phosphates to the water.
My phosphates are a modest +0.6.
Currently, I have set up a test aquarium where I intend to place individual pieces of my live rock in it and allow the phosphates to leach out. I am allowing any weed interested in participating to grow and I'll scrape that off and discard it as phosphate transfer.
Within a few weeks of adding the live rock, the phosphate level of the test aquarium drops to zero. The same happens with the nitrate level. I have to keep this going for a while to see if this method allows all the phosphate to leach out.
It's also interesting in that I see lots of interesting things being revived in the test tank, like a form a macro algae I thought had been eliminated altogether from the tank by my Yellow Tank (now deceased).
I don't have a sump, but obviously you could all do the same thing using macro algae in your sump, but you won't be able to examine the stored phosphate in each piece of liverock separately.
Henry,
interesting observations.
I was relieved to get a reading of 0.03 on the IBC water, after the inital 0.39, but I am told even 0.03 for NSW is actually high. I have big air stones in each of he 3 IBCs. Can it possibly be that the IBC water , which has been stored now for about 2 weeks, has 'accumulated' Phos in storage. ?
Visual inspections show the water to be clear. The 2 built under he new deck, at the water side, are inter-connected, and covered by the deck, so minimal sunlight. The top IBC at the road side, I have added the thick plastic sheeting, to shield from light. To move water from the 2 lower IBCs to the top one, we have a separate pool pump, which then runs through a canister filter before discharging into the top IBC.
We tried to think ahead, and take all precautions, but I am wondering if there may be something we missed.
I am encouraged by the much reduced readings, but fully intend to maintain the 2 reactors with Rowa Phos, and with the new full spec bulbs I hope the Chato compartment kicks it up a notch, and we get the levels even lower.
What is less encouraging is, I thought to help this along yesterday, and used the new gravel syphon to try to such away the Algae on the sand bed., It had limited effect - churned up the sand, but most just settled down the tube and back to the floor, with what I think is just covering the algae up, rather than removing it. The sand bed was noticeably whiter, but when I checked this morning, there seems to be new algae covering the sand.
I am wondering f I should resort to the old fashioned hose to syphon off the top layer of Algae, along with the sand. I could run the hose down to the basement, through the filter socks. I can then remove the filter socks, wash out the sand again, and return it. Noit sure if this is worth the effort. ??
From all I have heard, the fake rock I used, has been known, in some batches, to contain high silicates and phos, and then gradually leech it into the water. There is no clear indication of how long this can last.
I would be curious to know your test results.
Jac
