Welcome Nick D
How well did you clean the tank after the blackout? You should have done at least a 50% wc and then redosed your tank. Did you follow Tom Barr's instructions for hte blackout? If you did not get rid of a lot of hte dead plant and algae matter from the blackout then I am sure that is contributing to your secon outbreak. If your plants are not growing well (and there would be much organic matter from dead and dying leaves and roots. etc) then that will contribute to both the raising P and the algae problems.
What else besides TMG do you dose? NO3? You should have levels of NO3 of around 10ppm(to 15ppm) especially if you have that high of P. Cut back on your Fe dosing for now too.
I would recommend that you start doing 50% wc once a week and at tht time dose to 10ppm NO3 and dose smaller amounts of TMG everyday. Sorry, I can't help with that dosing as I have never used it. Make sure your test kits are accurate. Forget about the Fe test. Make SURE your CO2 levels are good adn don't trust your P kit (Forget the K test and dose 10-15 ppm at the wc).
To my knowledge, carbon will leach P that it has collected once the carbon is "full" which is why your test wiht a new cartridge tested 0. I would recommend doing away with the Carbon entirely. You are using a penguin filter right? If so take and old cartridge, rip off the old foam and carbon so you are left with the plastic frame. Then get your self some Blue filter foam made by Marineland (what I use), cut a piece a little higher(1") and a little over twice as long as the cartridge is high. Wrap it around the plastic frame and secure it with a couple of rubber bands. Stuff it back down into the filter adn change it in 3-4 weeks, or as necessary. You can stick a thin layer of fine filter floss between the layers of foam if you want. If you use the bio-wheel, stop
saves on CO2.
Hope this is helpful.
How well did you clean the tank after the blackout? You should have done at least a 50% wc and then redosed your tank. Did you follow Tom Barr's instructions for hte blackout? If you did not get rid of a lot of hte dead plant and algae matter from the blackout then I am sure that is contributing to your secon outbreak. If your plants are not growing well (and there would be much organic matter from dead and dying leaves and roots. etc) then that will contribute to both the raising P and the algae problems.
What else besides TMG do you dose? NO3? You should have levels of NO3 of around 10ppm(to 15ppm) especially if you have that high of P. Cut back on your Fe dosing for now too.
I would recommend that you start doing 50% wc once a week and at tht time dose to 10ppm NO3 and dose smaller amounts of TMG everyday. Sorry, I can't help with that dosing as I have never used it. Make sure your test kits are accurate. Forget about the Fe test. Make SURE your CO2 levels are good adn don't trust your P kit (Forget the K test and dose 10-15 ppm at the wc).
To my knowledge, carbon will leach P that it has collected once the carbon is "full" which is why your test wiht a new cartridge tested 0. I would recommend doing away with the Carbon entirely. You are using a penguin filter right? If so take and old cartridge, rip off the old foam and carbon so you are left with the plastic frame. Then get your self some Blue filter foam made by Marineland (what I use), cut a piece a little higher(1") and a little over twice as long as the cartridge is high. Wrap it around the plastic frame and secure it with a couple of rubber bands. Stuff it back down into the filter adn change it in 3-4 weeks, or as necessary. You can stick a thin layer of fine filter floss between the layers of foam if you want. If you use the bio-wheel, stop
Hope this is helpful.