Couple of questions for new planted tank

[Jeff1192]

Ok, I'm starting to get all my equipment together and I have a couple more questions. I am planning a 90gallon planted tank in October. I am picking up my lights on Wednesday. It's a 48" T5HO with 4 - 54watt bulbs. I am planning on using Seachem fluorite black as my substrate. With the cost of fluorite compared to gravel am I better off mixing the 2 or would an entire fluorite substrate be beneficial? I don't mind spending the money on a full fluorite substrate, I just don't want to buy things that are unneccessary. Also, with a fluorite substrate what fertilizers do you recommend adding to the water? And finally, I am not planning on doing a CO2 set-up right away, I was thinking I would wait and see how my plants do without it first. Just thought I'd mention that in case is changes any of your recommendations.

Thanks,

Jeff

[BigDaddy]

First off, you will be needing CO2.  4 T5HO's over the tank will require CO2 for sure.  If you don't wanna do CO2 to start, then only power up 2 lights if you can.

Flourite on its own is fine.. I have it in both my 75's.  Others have mixed and had no problems there either.

As for ferts, that depends on if you are firing the 2 bulbs or 4 bulbs.  If you do the 4, you are going to have to suppliment with N P and K (assuming you are adding the CO2)

[Jeff1192]

Yes I can control the number of lights that are on. The fixture has separate power supplies. I was figuring that at first I would only want 2 of them on, otherwise I'd have too much light without co2. So with only 2 of the lights running at first you wouldn't bother with fertilizer? As for CO2 where would you recommend getting the set-up? Is there somewhere locally that has good prices on the equipment? As well, for a 90 gallon tank how much CO2 would I be going through? I would probably only want a 5lb bottle because I want to be able to hide it in my stand.

Thanks,

Jeff

[BigDaddy]

There is a minimal size difference between a 5 pound bottle and a 10 pound one.  The only con is that you will be taking the 5 back in for a fill up twice as often 

If you intend on heavily planting the tank, you will still want some ferts to sustain your faster growing plants, but you certainly won't need nearly as much as if you were on co2/high light.

[dan2x38]

For the short erm you could use some Flourish Excel with NPK but it would get expensive fast... the Excel would deal with no CO2 for the short term...

BD was it you and/or Charlie who use the dry ferts? I don't but they are sure cheaper... liguid ferts are costly...