My first tank

[nimbusv]

Hi, i have a 20GL that i want to make SW, but i have a few questions.

i would like to put fish only, what fish could i put there?

is a Protein skimmer necesary?

do i need a special kind of lighting?

do i have to use a UGF? or a HOB is ok?

Thank you all

[mogurnda]

Welcome to AC! It's great that you're trying to get started right. I like nice, specific questions, it makes responding so much easier. Thanks.

The number of fish will be very limited in a tank that small, but it can be managed. I'd push for 2, matbe 3 small fish. Clowns and gobies are good choices.

A skimmer will be a big help in keeping the system happy, but is not absolutely essential. If you get one, get a good one (I like CPR BakPAk or AquaC Remora for small tanks).

If you aren't planning on keeping corals, anemones or other photosynthetic life, the lighting is all a matter of your pesonal taste. A cheap little striplight will do.

It's best to avoid the UG filter. I have run SW tanks for years with them, but have found that there are other ways (in fact most other ways) that are better. It will trap debris and give you trouble.
Instead, for biological filtration, a lot of people use live rock and live sand.

The best advice I think I can give you is about a couple of books that will help you to deal with all of the equipment and biology involved. For starting out with a fish-only system, I'd recommend Bob Fenner's Conscientious Marine Aquarist. John Tullock's Natural Reef Aquariums is also very good, and covers all aspects of marine aquarium keeping, not just reefs (despite what the title says). Both are less than $30. Forums are a good resource, filled with lots of good advice, but these books lay the issues out very clearly, in a way that isn't possible in short snippets on the forums. But don't hesitate to ask lots of questions here!

[nimbusv]

Thank you very Much Dave

one of the immediate questions that pop into my head is:

do Percula or Ocelaris Clownfish do well without an anemone?

[mogurnda]

They do perfectly well without an anemone. They breed them with nothing but a flowerpot, and most captive-bred clowns have never seen one. They will often try to snuggle with things, anything from corals to powerheads. My female likes to hold herself against a big toadstool leather.

[Spicy Rice]

Is it necessary to run a UV Sterilizer? Also, is RO water necessary, or will I be fine without buying a RO Unit? I have all the hardware that I need for my 50 gal FOWLR tank except those two things. I've already spent so much money on the stuff that I have. If I will be fine without spending the major bucks for those two things, then that would be great.

[OrionGirl]

A UV Sterilizer is not required--and I prefer not to use them for reef setups. They kill off all the free floating critters--ie, larval corals! Not good. Follow good quarantine practices, and you will never need a UV.

For RO--it depends on the quality of your tap water. You should be able to get a copy of the analysis from your water utility. From there, look at the phosphates, silicates, and nitrogen content. Also determine if you have chlorine or chloramines, as these will need treatment in some fashion as well.

[Spicy Rice]

How high should the levels of phosphates, silicates, and nitrogen content be to fascilitate purchasing the RO Unit?

[OrionGirl]

Less then .25ppm, I think. If you know someone else on the same water system with a reef tank, see if they've tried using the tap water, and if they had problems with diatoms and other micro algaes.