Ok. The consensus seems to be that I should try the dry ferts approach. Can anybody point me in the right direction for a good place to start with this?
....I have....jugs of flourish and flourish trace...can I just not use them anymore? Should I supplement them with something at first?
Also, how important is it to do a weekly water change? I've been doing a change once a month or every other month. I have a pretty low bio load.
OK, to start with I'd go over to nilocg. He has everything you need to get your ferts going. Great pices, great guides, great ready to go kits. Look for the EI starter kit, add an additional iron supplement if you want (I got ferrous gluconate but don't use it because I can't dose it correctly with my job). Mix the dry ferts in 2 bottles (one for macro, one for trace) according to the guide in their website. Then dose according to the schedule you want.
It's just tough to say you should stick with seachem because the math involved can be confusing and you have no real control. If you want more nitrates and less phosphates, well youre out of luck with seachem. You get more of both or less of both. In addition to this the "trace" minerals you get with a CSMB mixture is more complete than a flourish trace (I think, I could be wrong on that). Unfortunately I was in the same boat. Bought a bottle of literally every fert seachem offered. I ended up dumping 3 bottles to mix my own ferts. The rest, aside from Excel(which you can use in conjunction with dry ferts), are just sitting there. I'm keeping them in case someone I know starts a low tech tank, but in reality they'll probably end up down the sink so I can use the sweet sweet 500ml bottles.
As far as water change, just do it. I only have 7 fish and a few inverts in my 20 gallon with a huge filter and I still do it. It's as much about refreshing the system and removing excess ferts as it is about removing waste. If you go for a waalstad setup you really don't have too, but that's a completely different approach. In addition to removing waste, you're also adding minor trace elements from the tap water. Just generally balancing the tank. It's possible to ease up on water changes if you dose sparingly, but as you bought a co2 injection system, I imagine you want growth. It's hard to maintain a high tech and low maintenance tank, especially without very fine control over the ferts.
It's a pain to switch over, but trust me it's worth it long term. It's a pain to do weekly changes and do some reading about these chemicals, but it's as much about stability and keeping yourself sane as it is about removing the "bad".
These are just the things that have worked for me. They might not be exactly what suits you best. Hell I could be outright wrong with some of this info, I'm still learning. I think we are all though and that's what makes this hobby fun. I made the change about 6 months ago and I'm still riding the struggle bus, but I'm making progress. I'm sure you will start heading the right direction and find what works for you too!