Newbie Qs: Sump, lights, cover (action!)

Hi. I'm planning a new marine aquarium and have a couple of simple
questions that I just haven't come across answers to. The basic plan is
for a 75 gallon system, 80 pounds live rock, live sand, protein skimmer,
powerheads, power filter, heaters, lights... just the basics, but enough
to develop a decent system. So here are a couple of remaining questions:

Sump: What do you do with it? I know the idea is that the sump allows
you to pull water down underneath the tank to have more water and do
"stuff" (technical term), but what does it allow you to avoid in terms of
equipment up above? It seems that heaters and powerheads will still have
to hang in the tank, won't they? Can you do protein skimming in the
sump? Does it substitute for the power filter? Or does it allow you to
add additional filtration (which a beginner might not need)?

Lights: I've read the various debates that wattage values don't tell you
everything about light needs in a tank (it depends on type of coral,
depth, etc.), but for a 75G tank, 3-5W/Gal suggests 225-375 watts. I was
looking at power compact retrofit kits, and there seem to be two options:
4 65W bulbs (setups around $275), or 4 96W bulbs (setups around $400).
The 4 65W give the minimum lighting, which I think would be fine for the
initial fish-only setup. But then here are some related questions:
- If I buy a setup with 4 65W, can I just substitute in some 96W
later? Or is there different ballast and other components for the bigger
bulbs? Are the 96W bulbs bigger? Can you mix bulbs, e.g. 65W and 96W?
I'd rather spend $100 more now if I have to replace the whole thing with
a $400 setup in a year (if PC is how I go).
- Is it ever a problem to have too much light?
- Why 48" and 46.5" bulbs? Just in case you have a tight-fitting
hood and need the 1 1/2" of space?

Acrylic/glass covers: Many of the finished light setups have acrylic
covers to protect the lights from seawater. Retrofit kits don't. I
assume that you still want some protection from water splashes even if
the lights are mounted a few inches above the water. Where do you get
covers, or do you?

Thanks in advance!
Scott

your heater can be placed in sump as well as the skimmer. depending on the
type of system your going with (reef, FOWLR, or FO) will tell if you need a
"power filter" or not. reef's depend on the live rock and sand bed for
natural filtration, a skimmer helps reduce the need for water changes to
keep water quality in check. a sump can also consist of a "wet/dry"
(recommended in FO (fish only) setups)

lights................the watts per gallon is a really bad thing to ever get
your mindset on. wattage is best kept to "depth of tank, and type of light"
with surface area playing a partial roll in this as well.
on my 75 I have 800w of MH, it was a reef and done excellent with all
corals/clams. its now a predator tank, and other then sucking up all that
power and $$$ its still great.

the 4x96 would be in my opinion the better choice for a 75 gallon tank. I
have 4x65 pc over my 29 gallon reef and its not enough for higher light
demanding corals and clams. my seabe anemone is nicely colored and growing
but to be honest it would do much better with more lighting. 4x65 PC just
isn't enough and surely wouldn't be enough over a 75 except for softies
(shrooms, zoos and such).

with hard corals I honestly don't think you can have to much light, they
just have to be acclimated to it slowly. softies on the other hand can get
burnt/blistered quite badly even with very slow acclimation.

the different lengths of bulbs are mostly different mfg's not necessarily
for fitting in tighter spots, but it is a good side effect of the shorter
bulbs.

as for your question on the cover glass, I personally don't use one on
anything except HQI bulbs which require a UV protective shielding. any
glass/acrylic will decrease the intensity of your lighting and is IMO not
needed.

hope to have helped
kc

Very helpful, thanks. I guess I'm still concerned that water might
splash up onto the lights, which I read (and it made sense) as being a
Bad Thing. But I also see that every filter will diminish the intensity.
If it's pretty common not to have anything between lights and water (and
they will be probably 6" above the water once mounted), then I guess it's
not an issue. Thanks again. I've figured a lot out by reading, but
there are these small things that pop up here and there...


"Dragon Slayer" wrote in
:

[snip]
as for your question on the cover glass, I personally don't use one on
anything except HQI bulbs which require a UV protective shielding.
any glass/acrylic will decrease the intensity of your lighting and is
IMO not needed.


hope to have helped
kc