Hi Cody,
I saw somewhere else where you had a thread about excess nitrates. So if you'll oblige me. Assuming you are using ro/di water for both make up and salt water, and that it is filtered appropriately, then Nitrates are likely a primary result of food added to your tank. So the first thing you should think about is reducing your feeding. It seems everybody finds a comfort zone about how much food is too much or too little, but the truth is we all guess.
In terms of getting nitrate out well, 1) skimming will remove some, 2) any substrate will also remove some like live rock, live sand, dead rock, ceramics, heck even bio balls and no I am not advocating bio balls 3) algae via a scrubber, reactor or refugium 4) all those bacteria and critters that live in your tank as well so that is why carbon dosing also works. Although, I don't carbon dose, I do use a skimmer, I have lots of rock and sand perhaps not a deep sand bed, I utilize siporax, I have a refugium for chaeto growth and as I said earlier, I like to think I feed enough for fish health but not enough to create a nutrient overload.
I added siporax some time ago to my tank. Mine took about 4 months to "turn on". It requires time to colonize and I have heard it takes a couple of months to be seeded with enough aerobic and anaerobic bacteria (nitrifying and denitrifying) to become effective but I don't know what exactly is the time truly needed. It is pretty easy to tell when it is functional because it dramatically drops your nitrates so you have to keep testing along the way. Heck, you have to keep testing nitrates all the time regardless. I believe 1 liter per 25 gallons is suggested but I doubt that the amount is based on research, either anecdotal or marketing probably. I think I have about seven liters but I don't remember the exact number. I use the 15 mm size but again I don't know if that is any better or worse than the 25mm size. I have it in both my refugium and sump and both are after my sock. I don't have much detritus or debris in my sump ever because of the sock which I try to change out twice weekly but at least once weekly. I haven't "rinsed" or cleaned my siporax yet. It is recommended whenever you perceive a reduction in effectiveness which probably means it should be rinsed regularly so it is always well functioning. I think flow is probably not significant and would not suggest adding another powerhead in your sump to increase flow there. In some of the siporax literature it suggests flow rates do not matter although I thought I had read somewhere else that someone within Siporax thought slow flow actually might dramatically increase nitrate reduction.
Awesome thank you! I have a skimmer rated for 500g on my 180dt and 40 gallon sump, I have cheato that grows great but obviously does not take enough out. I have seen everywhere that everyone says to use the 25mm and not the 15mm but I have only really seen the 15mm for sale, so good to see you use it.
I really do not think I feed too much, as I feed my own homemade mix that is only around 3-4 frozen cubes which I do not think is a lot for a tank this size. my SPS are just not large enough yet to take up more nutrients which is why I was looking for around a 1 year solution like siporax to help control my nitrates till my SPS are taking up a lot more nutrients.