Coral QT Questions

[Itchy Trigger]

I have a 15g set up as a coral and invert QT. There's about 10 lbs of live rock in there. MaxiJet 600 & Koralia 425 for flow. Tunze Osmolator ATO. Ecoxotic Panorama Pro for light. The tank is simply for keeping new corals in quarantine for 10 weeks before introducing to my DT.

I have a six hour photoperiod with the light on there and do small weekly water changes. Still getting quite a bit of hair algae though. The corals aren't being overcome by it, and i clean it off the glass as often as I can. Harder to get it off the live rock though, which is where the corals are.

So I'm wondering two things:

1. As I currently have the corals just sitting on the rocks, might it be a better idea to get a rack for them so that I can easily clean that as algae grows? Perhaps two racks - and just rotate them weekly to keep them algae free?

2. Would it be a good idea to keep some sort of small fish or inverts in there that eat algae? Preferably snails, as I like to keep the tank fish free.

[Reef Frog]

There will be varying opinions on this. IMO I'd not add fish as you will be adding food to feed them. That means adding nutrients to fuel the algae, compounding the problem. Plus effective algae eating fish that are suitable for 15g are few & far between.

The rocks may be leaching PO4. If you keep removing the algae physically and add no food for fish & corals, nutrients should drop on their own. Water changes should keep nitrates in check. As long as the algae isn't growing rampant on the plugs or exposed coral skeletons, it doesn't sound like a big problem to me. How old is the set up? It will probably self correct.

Sounds like an excellent QT set up. Nice job.

[Reef Frog]

Oh, and a 6 hour photo period may not be enough long term for some stony corals. I would try to match all of the lighting parameters as close to the DT they're going into as possible. GL.

[Itchy Trigger]

Thanks! Yes, it's a relatively new setup, so I bet you're right. I'll up the photo period a bit and keep removing algae manually and doing water changes. And won't add any fish - I prefer not doing it that way anyway. :thumbsup:

[emerald crab]

I don't use live rock in my coral QT tank. Instead I have a mesh bag(from oranges or onion) filled with boiled "Hydroton" (if you don't boil it, it will float) in my sump. Whenever I need, I take the bag with "Hydroton", some water from my DT and I get a QT tank ready to go in no time. For coral QT I use small tanks, about 2 gal, with skimmer, ATO, powerhead and 10W hybrid LED light.
At the end of the QT period(6 weeks in my case), I discard the Hydroton clean the equipment with bleach and store it in my garage until next time.
I quarantine ONE coral/tank.

[organism]

A rack or two would be a good idea since the corals will also get more flow along with bring easier to clean. Also a six hour photo period is definitely not harmful for your corals when your tank has high nutrients, what is really harmful though is upping your light cycle while you're in the middle of an algae outbreak since it'll pretty much just end up eating your corals.

Plus it's your qt tank, you're not growing out corals in there so there are no long term issues with that light cycle, and since you want to acclimate new corals to your lighting anyway I'd say a 6 hour light cycle is a great idea for a qt tank. Instead of doing something potentially harmful with more lighting I'd recommend looking into carbon dosing if the tank has a skimmer or just keep up with water changes.

How high do you have your light's white LED's set? I find that when the whites are over 50% they can grow some serious algae.

[Itchy Trigger]

Good points! Will leave the photo period at 6 hrs. And maybe dim the whites down a little bit.

[organism]

What level do you have them at? I run mine at 30% ish, really cuts down on the algae and with the blues at 90-100% it makes the colors pop. imo it helps the corals acclimate better too :)

When I have bad algae outbreaks I'll usually leave the whites on for only 4 hours, the blues for 6.

[Reef Frog]

Yea 6 hours is fine on a temporary basis.

But for long term, 6 hours isn't ideal for some corals. Corals come from equatorial regions and have evolved over the eons on a 10-12 hour photo period of intense sunshine, often in shallow water. Especially with a lower power 1w LED fixture that will dim a little over the years.

IME you rarely go wrong mimicking Mother Nature to the extent possible. While I don't QT corals like the OP, I find it advantageous but not essential when I can buy corals that came from a system with similar lighting & PAR values as my DT lighting. They just seem to acclimate faster, many instantly. Longer photo periods should also encourage faster growth. But with all that said, I'm not implying that a 6 hour lights on cycle will be harmful to most coral species - many are quite adaptable, except maybe some SPS like across or birds nests.

If the algae is bothering you, I would concentrate on nutrient testing & export. In the end, eliminating algae successfully is always about nutrient control. Any gains from black outs or tweaking a photo period are usually ephemeral if nutrients remain high. But controlling nutrients should be relatively easy in an unfed, bare bottom fishless frag tank.

[Itchy Trigger]

What level do you have them at? I run mine at 30% ish, really cuts down on the algae and with the blues at 90-100% it makes the colors pop. imo it helps the corals acclimate better too :)

When I have bad algae outbreaks I'll usually leave the whites on for only 4 hours, the blues for 6.

Right now the whites are around 75% with the blues at 100%. Will dial the whites back to around 30%.

[Itchy Trigger]

Yea 6 hours is fine on a temporary basis.

But for long term, 6 hours isn't ideal for some corals. Corals come from equatorial regions and have evolved over the eons on a 10-12 hour photo period of intense sunshine, often in shallow water. Especially with a lower power 1w LED fixture that will dim a little over the years.

IME you rarely go wrong mimicking Mother Nature to the extent possible. While I don't QT corals like the OP, I find it advantageous but not essential when I can buy corals that came from a system with similar lighting & PAR values as my DT lighting. They just seem to acclimate faster, many instantly. Longer photo periods should also encourage faster growth. But with all that said, I'm not implying that a 6 hour lights on cycle will be harmful to most coral species - many are quite adaptable, except maybe some SPS like across or birds nests.

If the algae is bothering you, I would concentrate on nutrient testing & export. In the end, eliminating algae successfully is always about nutrient control. Any gains from black outs or tweaking a photo period are usually ephemeral if nutrients remain high. But controlling nutrients should be relatively easy in an unfed, bare bottom fishless frag tank.

The lights in my DT are on for about 10 hours, including ramp up and ramp down. I'm guessing that the algae in the QT could have been a result of the relatively recently added live rock, as you suggested. Will just keep on top of water changes & manual removal.

[organism]

Corals come from equatorial regions and have evolved over the eons on a 10-12 hour photo period of intense sunshine, often in shallow water. IME you rarely go wrong mimicking Mother Nature to the extent possible.

I think you need to dive some reefs, a lot of the non-SPS corals we keep aren't very shallow and don't get a full day's worth of light. More importantly, those "10-12 hour photoperiods of intense sunshine" aren't realistic since the sun is only at its strongest for less than half that time, while your lights are at their strongest for 100% of that time. Sunrise and sunset take a long time, and corals tend to grow around each other which blocks light too. The best tanks I've seen run the whites for no more than 6-8 hours, blues for longer though, just like in the wild. You've gotta study nature before you can mimic it :)

Longer photo periods should also encourage faster growth.

They don't, quite the opposite actually. Lots of studies out there.

[Reef Frog]

Interesting topic. I agree that most of the information you present is accurate but feel you're missing the larger & finer point in a few respects.

I was just saying that a 1W fixture with a 6 hour photo period would probably not be ideal LONG TERM for corals needing higher light. In fact it may cause decline, possibly quickly. No successful SPS keeper would recommend such an idea LONG TERM. I thought this was common knowledge by now. It would be more problematic the deeper the tank of course.

Of course the OP is just doing a QT for a few weeks & he will be fine - heck I don't even know what species he's keeping. I was just making an academic point so a a person beginning with acros for example didn't get confused if stumbling upon this post in the future. I realize it was a side comment that didn't apply directly to the OPs intentions but just wanted to offer it as a kind of warning.

It might just be fine LONG TERM for low light corals I suppose. Never tested it, never wiill. Have never even read about a 1w LED, 6 hr PP stony coral tank. But I know that my mixed LPS/SPS 18" deep 39w 6 bulb T5 w ATI bulbs tank would be a disaster under similar circumstances - long term. However short periods are fine - during the Sandy storm a few yrars ago I went almost a week without power. My power inverter could only run a crappy 2x 24" T8 shop strip with worn out yellow bulbs intermittently. I was worried it would totally skunk my tank but everything was fine. That showed me corals can adapt to less than ideal situations easily, which supports your good description on the variability of tropical conditions & how corals can adapt.

My main LFS has a small DT running with the OP's exact lighting (white/blue) for 4-5 years at least. It's a nice mixed stony tank with a few zoas & softies. It's lit 12 hours per day supplemented with the sun coming through the store windows, southern exposure. Chalices, plates, monti, acans & trumpets do OK but acros & some other SPSs do poorly....with 12 hour PP plus sunlight, and many are mounted high, close to the light. The tank is well maintained. The manager attributes all of this to the lighting as all other parameters are to reef spec.

Also, I did research months ago on RC on the OP's Exotech fixture (royal blue model) as I want to add something similar to my 6 bulb T5 fixture for the sole purpose of using it alone for short periods after lights out so I can enjoy fluorescence. Owners were pretty much in agreement that the blue/whites were not of enough intensity for many of the LPS & SPS corals they keep on a typical PP, much less a 6 hour PP. Many owners indicated they would be upgrading to 3w LED units, where it is common to run whites only ~8 hours as you do - but they mostly run the other spectrums for a longer total PP. Plus I came upon convincing accounts saying that the lights dim & lose radiance gradually over time which was new to me, but supports my point further if it's true.

My Quote:
Longer photo periods should also encourage faster growth.
Your Response:
They don't, quite the opposite actually. Lots of studies out there.
Rewrite:
Common photo periods of 10-12 hours likely promote faster coral growth long term when compared to a 6 hour photo period, all other factors being equal.

^ I wasn't saying or recommending 16, 17 + hours etc. I think that's what you were thinking? I was just saying a common sense schedule that mimics a captive animal's natural environment is best. Somewhat close to equatorial, not Siberia in winter. If you can find me a real peer reviewed lighting study saying 6 hours PP is the way to grow corals...well I'll eat an acan! :p Seriously I probably wasn't clear in my comment.

BTW I study nature intensely - it's my passion. :rollface: I'm sitting on my patio having a beer right now wondering how my sun loving wild flower garden would do in the shade of the deep woods. I've also made hundreds of dives all over the world in the last 20 years too! Yes you're right, many species exist in low & no light conditions in nature, and many where solar radiation was crazy intense in a few inches of water. And many species experience conditions between those extremes. But think of a shallow lagoon or the first few feet of a reef slope in dry season. I think an acro frag from there plopped in a tank under 1wLED on a 6 hr PP for 6 months might not be too happy!

Last point: Who the heck wants a 6 hour PP anyway? Seriously? I can miss seeing the tank with the lights on, even with a 12 hour period, if duty calls. I like watching the tank. The most comfortable chair in the house is right next to it for a reason!

SPS - Low powered lights - short photo period? LONG TERM? Don't do it!

[organism]

My Quote:
Longer photo periods should also encourage faster growth.
Your Response:
They don't, quite the opposite actually. Lots of studies out there.
Rewrite:
Common photo periods of 10-12 hours likely promote faster coral growth long term when compared to a 6 hour photo period, all other factors being equal.


They don't, quite the opposite actually. Lots of studies out there, starting with Journal of Experimental Marine Biology and Ecology, Volume 298, Issue 1, pp 35-48. All I'm saying is there's a lot more to the hobby than it seems, and since you love to study nature intensely then you'll probably find a ton of stuff you never even though of by researching the peer reviewed studies out there :)

At the end of the day lighting on a QT tank doesn't really matter, but you may want to make one down the line since your habit of not using one will eventually backfire like it has on all of us :D

[inktomi]

I'm also looking at starting a small coral QT tank. On a 10 gallon tank, do you really need a skimmer? I have two extra MP10s which I was going to use along with a Kessil A350 (since I have it on hand)... but not sure how I'd set up a skimmer on this tank.

Other than that, just a piece of PVC elevated egg crate for the coral frags.

Assuming weekly water changes, and using the tank more for ensuring there's no algae on the frag plugs, red bugs on the acros, etc.. is a skimmer needed?