Join Date: Jan 2005
Location: Miami Beach, FL
To address the original questions:
"I see that Flourish makes Flourish Potassium, Nitrogen, Phosphorous. Do I need these others? Does anyone use the Flourish line?"
- I dose Flourish, Flourish Excel, Flourish Iron, Flourish Potassium, Flourish Nitrogen, and Flourish Phosphorous. This allows me to cover all three macros and the Traces Elements with one line. It is working for me (amazing growth, limited algae), but I have a small tank (15G). With a large tank, I think Flourish is just too expensive. When I run out of my current set of Flourish bottles, I am planning on switching to a cheaper alternative and adopt the EI dosing method (Tom Barr's Estimative Index fert method)
- You need macros, and I think the experts on here are will strongly recommend that you get some one way or another. The only thing that throws me is that you said your plants grow well. I can't tell from your post if you have an algea problem or are simply worried about a possible future algae problem. If you don't have algea, then things are working great, your fish/animal waste product must be providing enough macros, so why change a thing?! If you do have algea, then the probable cause is a lack of macros and you need to test for Nitrates and phosphates and dose macros accordingly. I'm no expert, but from what I have been reading, a good target range to aim for is about 15ppm Nitrate and 1ppm phosphate.
"Also does anyone use Phosguard? Detox 2, Seagel?"
I think that the general consensus of experienced plant people is to avoid these products, they introduce an unnatural variable into the equation. Instead of trying to chemically remove the phosphorous, you should instead encourage your plants to use up the phosphates before the algea can use it. This usually means adding Macro nutrients in sufficient/balanced quantities. Achieving this balance is the hard part. If you stumble across a dosing system that allows plant growth and avoids algea, don't change a thing, but if you are not so miraculously lucky, then you need to aquire a good nitrate and phosphate test and dose the macros.
- The 20" light, is it gonna go on the 18Gallon tank? If so that is a boost to lighting, and will make the macro requirement even more necessary to avoid algae.