Maximizing plant growth in a puffer tank

[MacTech]

I have a decidedly low-tech setup that i'm trying to maximize plant growth in, the current hardware setup is;

20 Long tank
about 3" of very fine gravel
Penguin Emporer 280 Bio-Wheel filter
Ebo-Jaeger 100 W submersible heater
20 watt flourescent hood with a Coralife Nutri-Grow plant lamp

plants;
a large clump of Java Moss (softball size when bunched up and held in my hand, not a bad deal for $3.99 from my LFS, the fish guy just stuck his hand in the plant tank, grabbed a handful, and rang it up, normally their "handful" is golf-ball sized)

a sword-ish looking plant, faint green leaves, rose-ish shape, i didn't get the name at the time, it looked nice though, they had it floating, but it could supposedly be planted or free floating

and the newest addition today, Cryptocoryne Wendtii, seperated from the bunched up, rootbound pot, and each plantlet given about 2" of "breathing room"

Animals;
5 Dwarf Puffers (currently about 3/4" juveniles)
6 Ghost Shrimp

first off, i realize that my animal biomass in this tank is low, the tank's definitely understocked so i realize i'll have to fertilize the plants, as they're not going to be getting much nutrients from fish waste, more to the point, what would you experts reccomend to maximize the plant growth

from what i understand, my total light wattage of 1 watt/gal is reasonably low, but the tank is a 20 Long, so the distance from the gravel surface to the light is just a hair over a foot, so i'd imagine the formula of watts-per-gallon doesn't strictly apply to a 20 LONG, if it was a standard 20 or 20 High it would, the tank's pretty darn bright as it is, and the gravel is white, so it reflects a good amount of light back to the plants

would CO2 injection (either DIY or the Hagen thingy) help, or is it not neccecary in a 20 long, my LFS said they tried the Hagen thing and got an overgrowth of algae in a few days, they don't reccomend the Hagen system in a 20L

what would be the best way to turn my tank into one of those attractive "underwater gardens"?

[all4funwfish]

your light is low. even for a long. you should get anubias and java fern. i dont use co2 in any of my tanks, and getting the ppm right is a little difficult in small tanks. i would recomend plant care tabs that add trace elements and co2. get a reflector for your current light setup. wpg is really not the key factor, its lumens and color temperature. adding the reflector will increase the amount of light reaching your plants. color temperature should be around 5500k or 6500k, although you can grow plants with less. you will see the difference in lighting instantly between say a 4500k and a 6500k. everything will get darker and greener (plants). the rest of your equipment sounds up to par, although you can get better substrates, its really not necessary for your lower light. less light is less growth and less growth is less nutrients being used. anytime you change water parameters drastically like by adding co2 you get algae, which is why your lfs had algae. they had an overdose of nutrients, in this case co2 and not enough plants or lights to use it all, so algae used it. allow the tank to balance itself out before you condemn something. good luck!

[MacTech]

Thanks for the info, i figured CO2 probably wasn't neccecary, but with me being a tech, i thought it would be fun to build a DIY reactor, so i have one happily bubbling away in the tank now

my unscientific design is as follows;
standard soda bottle DIY reactor, blowing thru one of those "bonded glass bead" superfine airstones, to slow down the CO2 bubbles.

my "diffuser" consists of putting the airstone under the thicker part of my Java moss, in order to prevent CO2 overdose in the tank, the java moss is situated under the outflow of my power filter, if i understand it correctly, the surface disturbance disperses CO2, so the only CO2 that remains in the tank is what's been trapped by the Java moss, the moss is dense enough to give the bubbles time to enter the water collumn

as it stands right now, the airstone emits about 5 bubbles per sec, and the bubbles are tiny (1mm or so)

the DIY reactor is simply an experiment, if it doesn't work out, i'll just scrap it, i figured it made more sense to do the DIY route first and if it works, go with the Hagen device

fertilizer makes sense, dwarf puffers and ghost shrimp aren't exactly a massive bioload, so the plants won't be getting much food from fish waste, so the plants need food from another source

what's the best fertilizer, the Flourish line, the Sera line, what?

the final addition to the tank will be a small group of Otocinclis catfish, right now i'm getting a small growth of brown algae on one of my rocks (this was before i set up the reactor) and some of my java moss is beginning to come down with black hair algae (yes i know, i need to add more light), but those fragments of fern end up in my snail breeder tank as snacks for my brown rams and pond snails

[all4funwfish]

sounds to me like your co2 setup should work fine, only problem people seem to have with the diy method is an inconsistant flow of co2. its really not rocket science. for your algae i would also consider some amano shrimp. cory's make good fish, but tend to like groups, so get 3. amano shrip should be like 1.99 or so, and dont have the hump in their back like the ghosts. a lot of people use flourish. they are pretty good fertilizers. you can also get under substrate fertilizers, that come in a stick. im not sure of the brands on these, but they tend to last a long time as opposed to the weekly(?) flourish. if you ever decide to change your substrate, use flourite or eco complete, whichever look you like best. eco is black, and flourite comes in browns and reds and river bottom looks.