Starting my first saltwater tank
 

Plan
>20G tank FOWLR
>20lb live bahama sand (have)
>10lb eco reefer rock (have)
>10lb live rock/live rock rubble (have)
>Hydor koralia 750
>Aqua Clear 50
>Eheim Jager 150w
>Refractometer (from ebay)
>Coralife salt mix (have)

>2 Ocellaris clownfish

so far i have 1/3 of the equipment, with another 1/3 coming in through mail.

got questions that some of you more experienced people can answer.

1> whats the best salinity level for me? (this tank setup will be FOWLR, no plans for corals/anemones)

2> how deep does the sand bed have to be in order for nitrate consuming bacteria to form?

3> what do you all think of my current aquascape? (possible too much deadspace?)

Welcome to the hobby! Sounds like you're on your way to to nice clownfish tank. Aquascape looks good (though the picture is a little dark... hard to tell exactly). But you can always rearrange it later if you don't like it. :)

A 20 lb bag of sand should be deep enough in a 20g to produce a deep sand bed. I've only got an 1-2 inchches and I can see bubbles of nitrogen coming up through it. I should add more sand though. 2-4 inches is a good depth in my opinion. try and add a couple of sand sifting snails. They will help keep the sand bed nice and healthy.

Jager heaters are good. I've had one for 10 years and it still works fine. A 150watt might be too much for you though... that's what I have in my 60 gallon! Maybe try 75 or a 100, then if it does get stuck on, it won't cook your tank quite so fast.

anyone know whats the best salinity level?

i heard 1.022 will be hard for parasites to attack fishes

A good salinity would be 34ppt at 78 degrees which is 1.024 SG. You can go higher or lower by 2ppt if you chose but you won't notice a difference and aiming for the middle will give you a little more tolerance since hydrometers and refractometers aren't always that accurate.

A deep sand bed will do nothing for you in that tank except reduce your volume. I would aim for a max of 1" depth. Setting up something for denitrification in a 20 gallon isn't worth while as water changes will be cheaper and much more effective.

Rock looks fine, it's not a real science so really whatever looks good to you will work.

You'll have to go much lower for this to be effective which isn't good long term.

Welcome to the hobby! It sounds like you are off to a good start. As far as sand beds go I would only put a shallow one in or none at all. I have a 25g reef without a sand bed and it doesn't take long for pieces of rock and rubble to start covering the bottom. I chose to go no sand bed on this tank because wastes don't collect and decompose as readily and any tank I have went bare bottom has never had any type of algae or cyno issues.