i wouldn't. you need to have your macro nutrients NPK. those are in comprehensive.
i would use comprehensive, trace, and excel. you don't need to have excel when you have co2, but i use both in one of my tanks and it does wonders
i was suggesting he get the comprehensive as he didn't have it on his list. he did however have excel and iron on his list. since he will be adding co2 and monitoring it with only 2wpg i see no necessity for excel. henceforth swap out excel for comprehensive. iron is not a bad thing to have around. most dosing regimens do contain something that is fortified with chelated iron though and with his substrate he may not need to dose it separately for a while or at all. only time will tell imo.
those should work fine for now. if you decide to go dry that should give you bottles to make stock solutions also. the bottles usually come in 250ml and 500ml (respectively 1/4 and 1/2 liter) which makes things handy.
if you decide to go dry i would start off with these taken from the link i posted earlier:
"One Pound of each of Aquarium Fertilizer/Greg Watson's Chemicals will last at least 1 year:
Plantex CSM+B
Potassium Nitrate KN03
Monopotassium Phosphate KH2P04
Potassium Sulphate K2S04 (optional)"
like i mentioned before it's not a bad idea to add toms (gregg watsons) gh booster and iron to the list. i personally don't use the k2so4 so you could nix that from your list. i also don't use the kno3 usually as i keep a well stocked tank and my nitrates are always in a decent range. if you don't want to waste a lot of money on root tabs and you think you may be interested in some heavy root feeders in the future having these around can make things real cheap and easy when it comes time to make some root tabs. alot of people just rely on dosing their water column though. maybe not the best approach, but it works.
anyway if you decide to go with a name brand like seachem and then switch to dry you will see the difference in price bigtime and more than likely effectiveness imo.
Once you get the hang of it, dosing dry ferts is a breeze.
As dundadundun mentioned you can also make stock solutions, rather than dosing directly to the tank. I've yet to try it myself but I've been told its a fairly easy method.
yuppers pappy... 1 tablespoon makes 250ml of plantex OR kh2po4. for ei dosing (i have not tried it yet) theoretically 4 tablespoons would do the same for kno3. or you could do 1 and dose 4X's as much on the nitrates. like i said i have not tried it yet so i have no idea of the solubility of kno3 (wether it will stay in solution or not).
remember though dosing suggestions are just that... suggestions. each tank is different and you'll want to test to be sure you're getting to your "ideal range" and not over. it will take some time and practice.
Which is why dry ferts tend to be easier...you can tweak you dosing to fit your plants' needs.
Granted, even sometimes no tests are involved, especially if you are particularly good at catching nutrient deficiencies on your own. Tom Barr doesn't even recommend it for beginners. Just play around and see what happens...
Ok when I'm starting off with just the iron trace etc. Do I need to watch my levels then? Or will I only have to worry about this when i run out of liquid test and convert to dry?
