I thought from the instructions that it is suggesting to first test the level of phosphate, then assume 2-4 times that is in the sand, so if the PO4 is high +3ppm you divide the recommended aquarium size by 2-4 times. Making the recommendation 100g for 25-50G ?

Yes I would assume so

The 3ppm come from the rowaphos website where it states 100ml removes 3ppm from 100 usg of saltwater. My tank reading is usually around .25 but I am assuming the rest is being used up. I also don't have a HANA so its not the most acurate reading.

I picked up my package and the reactor is a lot bigger than I was expecting. The reactor instructions say to use a minimum depth 2" which is going to be close to 100ml.

So I have a couple of questions. Can I get away with less than the minimum 2" depth? Would that be a hard rule or can I try less and see if I can get the correct flow? The reactor has sponges that are rather coarse. Do I put the the gfo directly on the sponge or add a layer of filter floss? The instructions for the rowaphos say it can be sandwitched between layers of filter floss but I don't think that was for use in a reactor.

You can get away with less than 2" depth, all you have to do is turn the nozzle to control the amount of inflow from the pump to the reactor. Make sure that the GFO has a slight tumble, with 30 grams of GFO you won't need alot of pressure for it to tumble, that why the output of the water volume is very low and that's why it would take some times for all your water to cycle through the reactor. Eventually you want to increase the media to remove the phosphate in your water and starve out your algae. If your phosphate is high I would replace it often. If your system is low nutrients the GFO can last over 6 weeks but I replace mine every month, I've never seen it last longer than 6 weeks.

Thanks for the help, I really appreciate it! I have it up and running. Not sure on the tumble, it may need more media. I'll watch it and see how it goes. I'm not looking to starve out my clam but I would like to finally beat the algea issue. This was supposed to be a mixed reef when I started it over 3 years ago but I havn't been able to get it stable enough to even think about sps. The algea is hopefully this last hurdle and with any luck this will do the trick.

Clams feed on nitrates :)

I would suggest you run Prodibio Bioclean also if you want to control your nutrient issues. For $55 you get 15 vials of biodigest (Nytrifying Bacteria) and 15 vials of Bioptim (Food source for the Bacteria) you only need to dose 1 vial of each every 2 weeks for your size of tank, these vials will last you 7.5 months quite a steal IMO, on bigger system it get quite expensive but with you tank you will get away with it cheap! Dose the prodibio every water change and watch your nutrient levels goes down :) over couple of months it will bring you down to ultra low nutrient levels. Do a little bit of reading on Prodibio and test it out of you like. I love this stuff esp when i get to break the tip of the vial and dose it into my tank :D most fun 2 sec I have LOL

I actually wanted to give it a try but can't seem to find anywhere to buy it.

Message Michael from aqua digital and he should be able to tell you which stores in BC carries it. If you don't mind paying shipping cost then the online stores are cheaper than in store ones usually. Reefsupplies and Goreef carries Prodibio.

Everything is up and running with no major issues. However, my skimmer has stopped producing since I fired up the reactor. There are bubles forming like crazy but only about 1/4" of foam on top of the water. I have seen this happen for short periods of time after feeding but it hasn't produced anything in 48 hours.