Too much light? Seriously

[ouling]

I've always been the one to say that you can never have too much light, but I thought about it over with my new tank setup.

The tank will be 48X18X17, and the lights are 48'' with 2 400W SE running on a PFO HQI (DE) Ballast.

I got mirrors on the bottom of the tank, and it will be bare bottom. I hear that corals will bleach with no sand bed if there is too much light, and if I want to keep the lights, I must compensate with a huge sandbed...

More Food = Corals able to take more light???

I'm an absolute :noob: to the whole BB deal, and more likely I will have a 5'' deep sandbed on a 30''X18'' tank bottom with alot of rock work in there.

Any advice please??

 

[cameron]

MH or any other man made light for the most part are very dim versions of sunlight... it is virtually impossible to have too much MH light for SPS. You can shock them, but once acclimated you can beat down all the MH they can stand for the most part.

Not sure about the mirror part... seems strange.

 

[theplatypus]

I would do some reading about running bb tanks or you'll probably have some issues. In general, the successful bb tanks are heavily stocked and fed large quantities of food. They run shorter photoperiods with less lighting than tanks containing sand beds. A lot of them are topped off with saltwater, not fresh water. WHy? Because when running a bb tank you should be skimming very wet. People are removing gallons a day via the skimmer.

 

[simon_kruger]

I have a theory that the light in your BB might be reflecting back up on the underside of the coral. This might cause problems as this has never happened in the wild and the coral may not be able to handle it.

I just saw Alan's BB and he had it painted black. It looked absolutely awesome. One of the best kept tanks i have seen for a while. Polyp extension was excellent, colors were good.

Thinking about going BB myself. But I would go black bottom.

 

[jeep9783]

If u don't have a sand bed does that meen that u have do dose phyto more, is this what u are talking about when u say that

 

[cameron]

If you are putting a mirror on the sandbed, you have to install a disco ball somewhere along with some spinners on the pumps. Pimp that tank!

 

[wbholwell]

and different colored moonlights that flash on and off

arty:

 

[kwl1763]

I've had my 450G barebottom setup for a year now and had a 135 BB for 3 years before that. All kinds of misinformation going on here.

1) It is true that with a light fish load you could very well have to supplement stuff you would never "normally" want to like nitrates. I experienced this until my fishload was up to par that my corals were pretty washed out but the last few months have been fine.

2) No matter what you do on the bottom it will be covered by coralline withiin a month or two anyway so who cares! I personally used black starboard but even mirror will only reflect light until it covered!

3) I don't skim wet or topoff with saltwater. In fact of the many I know doing this most of us skim "normal" and nothing like gallons per day!

4) I do think that in general BB needs less light but only because there is less nutrients in most BB tanks. It's an interesting concept Simon but like I said once the coralline sets in it's a mute issue!

5) You will have to vacuum the bottom or you'll get a sandbed! The detritus will build up it whatever slower flow sections you have, so plan for access to do that. I do mine about once every 2 weeks. Some do it every month, some do it every week!

BTW I love DSBs also. It's just different ways of doing things. I think a hardcore SPS tank a BB is great. For anything else I would do a DSB (and have in fact)

 

[theplatypus]

3) I don't skim wet or topoff with saltwater. In fact of the many I know doing this most of us skim "normal" and nothing like gallons per day!

THe reason you skim wet is to get the detrital matter out before it breaks down. In large systems with it is by no means uncommon to skim gallons a day. Why would you top off with saltwater? You're not losing the water to evaporation so the salt isn't left behind. SO if you topped off with fresh water you would constantly be lowering specific gravity.

4) I do think that in general BB needs less light but only because there is less nutrients in most BB tanks.

Sort of correct

5) You will have to vacuum the bottom or you'll get a sandbed! The detritus will build up it whatever slower flow sections you have, so plan for access to do that. I do mine about once every 2 weeks. Some do it every month, some do it every week!

If you have enough flow and cooked the rock to remove all of the built up detrital matter there would be very little to siphon. THe idea behind bb tanks is to keep the detritus in suspension by using high flow and removing it before it breaks down by skimming wet.

 

[glxtrix]

I had a BB and I'll share some of my exp with it....I'm not going to argue anypoints because its completely useless to do so in this club because everyone have their own oppinion.....I had a 15g BB with a lot of flow. I suggest you worry about this more than anything, you need to get that crud stirred up and in the water column and to your skimmer, it does no good sitting on the bottom of your tank and will cause problems. So get flow going in there, and have flow on the bottom of your tank so nothing will settle. I had a heavy bioload for my tank, plus side to that is I rarely fed my corals....come to think of it, I really dont feed corals anyways....I let the fish poop or whatever food is thrown in there for the fish get to the coral. I had a 175W MH blastin on my corals and in a tank thats about 12" high....light was no concern. Skimming is a big part here but you dont need to skim extremely wet, but you do need wetter than dry. really its up to you and how comfortable you feel with wet skimming, just watch your salinity cuz you are pulling SW out, but not huge amounts. As far as a shortened light period...I dont think I've heard of that, I ran my lights the normal 8.5-9hrs and my corals loved it! I had starboard on the bottom of my tank jsut the regular white stuff, it was covered with coraline within 4 months so the mirrors really wont do much for ya. Thats all I think i have to say, if you would like to talk about it feel free to PM me and I'll help as best I can.

 

[ouling]

I had a 15g BB with a lot of flow. I suggest you worry about this more than anything, you need to get that crud stirred up and in the water column and to your skimmer, it does no good sitting on the bottom of your tank and will cause problems. So get flow going in there, and have flow on the bottom of your tank so nothing will settle. [/QUOTE]

Exactly what I will be doing. I'm going to put two Koralia 3s and Two Koralia 4s.

each one of the 3 and 4 will be aimed at the bottom of the tank, if the detris isn't stired up, then it will settle in the middle and i'll vacume it out.

Thanks guys

 

[ouling]

leveldrummer;63466 wrote: not to hijack, but what is the point of going barebottom unless your putting so much flow in the tank to keep the detrius in suspension? why would you have a bare bottom tank with no flow so you still have to vaccum all the crud out? might as well have a sand bed.

Are you talking to me? I am going to put massive amounts of flow in my tank.

 

[kwl1763]

You'll have some deadspots no matter how much flow you create. live rocks and just the nature of having a rectangle will create them unless you want like 24 powerheads! That's why you'll still need to siphon on a tank of any size. I know at least a dozen people with BBs for more then 2 years and they all vacuum at least monthly. Maybe on a 15G you won't need to but I still would!

The skimming thing is totally independant of BB in my opinion. skimming wet vs. dry is always debated and just a choice. I personally skim pretty dry. Of the folks I know barebottom I would say like half skim wet and half dry. I for sure don't think this makes or breaks anybody! And obviously if you skim extremely wet you will have to watch salinity closely!