HELP with 55 gallon tank!! HELP!!

[yanfloist]

I am starting to plant my 55 gallon tank. My 55 gallon has been running for 2 years now, I use to have other fishes in it but now plants. I have a lot of questions:
I am using two power filters. Is it true that surface movement/agitation is not good for a planted tank??
I keep the water temperature at 78 degree F.
pH is around 7.2-7.4
Kh hardness is around 8 degrees.
I only have two types of plants so far: baby dwarf tears and broad leaf ludwiga. I am planting the BDTs all around the ground. I want to make them spread like a carpet.
I am only using regular play sand, is that okay?? I think the sand depth is not deep enough. If so, can I just add more sand on top of the old one??
I am using one 150watt Metal Halide light.
I am currently leaving my lights on for 12 hours a day. Is this TOO much light?? If so, how much light do plants REALLY need to THRIVE??
I am using pressurized CO2 - 15lb tank with a regulator. However, I don't have a reactor so I am not using CO2 right now. How long can I go without CO2??
I use API's Leaf Zone for plant food and I am also using API's algaefix for alge control. Do these products work well??
I have two large Siamese algae eater in there right now and nothing else.
I don't want to kill these plants and animals so is there anything else I need to know??

[bettaobsession]

I am using two power filters. Is it true that surface movement/agitation is not good for a planted tank?? From what i have heard it is not so good for a planted tank but that is based on bubblers. So I am not really so sure.
I am only using regular play sand, is that okay?? I think the sand depth is not deep enough. I think so but i have never used it so...
If so, can I just add more sand on top of the old one??
I am currently leaving my lights on for 12 hours a day. Is this TOO much light?? If so, how much light do plants REALLY need to THRIVE??
I am using pressurized CO2 - 15lb tank with a regulator. However, I don't have a reactor so I am not using CO2 right now. How long can I go without CO2?? http://fish.mongabay.com/plant_care.htm
I use API's Leaf Zone for plant food and I am also using API's algaefix for alge control. Do these products work well?? I have never used them so I probably couldn't give you good advice. sorry.
I have two large Siamese algae eater in there right now and nothing else.
I don't want to kill these plants and animals so is there anything else I need to know?? I would just like to tell you that SAEs get very aggressive and territorial as they get older and bigger. Mine is VERY mean and lives by himself.

Sorry there are so many blanks, but hopefully this helped a little. Hopefully an expert will jump in anytime. Good Luck:)

[jbradt]

If you're injecting CO2, surface agitation is not good, because you will off-gas the CO2 back into the air. If you are not using pressurized CO2, then it's not such a big deal.

Play sand should be a fine substrate, but with that much lighting, you may want to consider a fert regimen, and root tabs for high root-feeding plants.

Temp, ph, kh... should be fine. I would reduce the amount of time the lights are on each day to 8-10 hours. Most likely, with the set-up you described in the OP, you are going to see some algae issues without CO2. With the amount of light you have, I would make it a priority to get CO2 up and running. You can go a long way with Flourish Excel, but CO2 will be better for your plants.

I don't recommend chemicals for algae control. Many times they contain ingredients harmful to FW inverts such as copper. Algae control can be accomplished without chemicals by finding a good balance of fish/plants/light/ferts for the tank. Leaf Zone is a decent fert, but with the amount of light you have, I would begin looking into dosing regimens of N,P,K, etc. as well.

[mott]

I always say start your photo period low like 6-7 hours then move up in time if needed.
Until you get the reactor going just stick a chopstick into your Co2 tubing it works pretty good as a diffuser!