corals dying slowly

[adamRS80]

My corals have been dying slowly over the past month. I moved my tank in January and drilled it/added a sump. I also downsized my light from a 250w MH 14k to a 150w DE 20k. The corals in the picture below are the ones that are dying. They’re either bleaching or their tissue is receding. I does B-ionic and have been for years, I have not switched salt types, still using Aquacraft. I did switch from using HEB purified water to my own RO/DI Kent Maxxis. Before I moved my tank it had 6 powerheads on a wave timer, now the tank is drilled with a Mag 9.5 and 3 maxi-jets. The temp is 82-84 always. I have a remora skimmer, and a small refugium running in the sump. I have not made any changes other than those listed above. I have no idea what could be causing this. My tank is the same as it’s been but with more flow and I guess a little less light. My zooanthide seem to be doing great and some of my SPS corals are fine but my blue chalice is dying because the tissue is receding underneath it, my elephant skin coral has bleached but is alive, and my pavona is nearly toast. I thought thing would turn around after a few nice water changes but it’s not getting any better. Please ask me any questions so I can help pinpoint the possibilities. Thanks for your help.

[adamRS80]

few more pictures

[Richard]

I would check your water (Ca, alk, nitrate, etc) just to see if there's anything you could do/improve to help them recover. Those are all high light corals and since you downgraded a bit I think that is definately something you could improve. The acro in the first pic looks like he could use more light for sure. Do you keep it down on the substrate all the time?

[RobertG]

Lighting & Tempature would be my first guess. 82-84 your not to far from cooking them. As Richard is hinting on, they do seem rather low in the tank. Let us know the parameters you have at the moment.

[Tim Marvin]

From a 250w 14k to a 150w 20k is a huge down grade in PAR. I'm betting on the lights being the problem. Personally if I was switching to a 20k I would have gone to 400w DE. Sell off all the high light corals before they completely die or add some T-5 lights. I'm sure you don't want to move back up to 250w halides. I haven't seen any use for a 150w halide except for maybe a refugium. You can get better color and light out of 4 /T-5's . This is only my opinion though.

[matt]

The lighting is suspect, but I'd also consider the possibility that something's up with your sand bed if you moved it. If you had a deep sand bed and moved it, you might have caused some mortality in the sand which could lead to some low level pollutants in the water. You might try a DOC test, or ORP. It might tell you something. First and easiest thing to do would be to replace your 20k bulb with a 10k ushio or XM. That'll get the PAR up somewhat. You don't say how big your tank is, but if it's anything over a 30 gallon, I personally don't think the remora is enough of a skimmer. You might try an EV120 if you like aquaC skimmrs, or the remora pro with the mag pump.

Getting back to the sandbed, if you have one, try getting some good live sand with lots of life. You could get some from inland aquatics, plus a few dozen bristleworms. Tim Marvin used to have really good live sand; if he still sells it, try getting some from him.

[adamRS80]

Thanks so much for the advice. I suspected the lights for sure but I thought that DE lights were very powerful so I figured it might be enough. I didn't want to use a 20k bulb but since I don't have any actini supplementation I figured I needed something with a little higher kelvin. My sand bed is pretty much completely new. I tossed all my old sand because I thought I would be better off starting fresh than disturbing my old one. I would have had to move the old one twice in a month and I just didn't want to risk that. As far as the Alk, Calcium they stay pretty stable...alkalinity test give about 3.0 and calcium is 450.
The RO/DI system has had less than 200 gallons through it. I have not tested it though but I'm going to try and get my tank water and RO/DI water tested this weekend.

The tank is 46 gallons but the skimmer seems to be adequate, I only have 3 fish, 1 small regal, 1 black percula, and one firefish. I purposely didn't want to overload it because of my skimmer size. I used to just have 1 CPR and I was fine, although it stayed pretty busy.

So if I switch to a 10k DE and add maybe 2 actinic T-5's does anybody think my lighting would be back on track. I was trying to save money and keep my system simple and clean looking so I sold my old 250 system which was about 7" above the water and over a glass lid. This system is 5" above the surface with no lid. Is this light really that weak?. I had head that DE metal halides put out a lot of light, I probably should have asked more questions here. THanks for the help. So is it a new light altogether, or should I just replace the bulb and add some t5s?

[adamRS80]

What about this fixutre below? I'm trying to keep my tank looking nice and clean without all the clutter. Is the 150w DE really not powerful enough or is it the fact that I'm using a 20k bulb with not supplementation?
Am I going to have to go back to 250w SE?

What I have currently
http://www.hellolights.com/aqadhatamo.html

What I'm considering...
http://www.marinedepot.com/aquarium_lighting_metal_halide_current_usa_outer_o rbit_hqi_actinic_lunar.asp?CartId=

Or just go back to the 250w SE?

I'm going to try to do something quick because I don't want to lose anything else.

[adamRS80]

Or....
http://www.marinedepot.com/md_viewItem.asp?idproduct=AQ1811

[Thunderkat]

I also downsized my light from a 250w MH 14k to a 150w DE 20k.

Before I moved my tank it had 6 powerheads on a wave timer, now the tank is drilled with a Mag 9.5 and 3 maxi-jets

Less light and less flow maybe? (Edit: Less flow and less light compared to what you had before- you downgraded your lights and now have less powerheads).

Also how long has it been since you changed your cartridges to your RO unit and how long have you used it?

I am not a coral expert but those things jumped out at me.

[adamRS80]

The RO/DI unit was new in January. I don't think it has more than 200 gallons through it. I have a flush kit on it as well to keep it lasting as long as possible. I don't know if there is too much flow because the Mag 9.5 is split into to returns and they just don't seem to stir things up, and the maxi-jets are alternating so never more than two are on at once. I'm not saying the flow isn't the problem, but I don't think any of the corals are being blasted.

[z28pwr]

I've got a TDS meter (just needs new batteries) if you are by the Medical Center, otherwise another member may be closer.

[adamRS80]

Any comments on those lights I posted? I don't want to be short on light, but I hate to spend more than I need to. I thought that 150 DE put out some pretty intense light. Would a 150 DE with two 65w PC not be enough for this tank? I do plan on keeping some clams. With any of these lights I would be using a 10k bulb with actinic supplementation instead of just having one source of light which is what I have currently with the 150 DE 20k

[GaryP]

1. Remember that the PAR on a 20K is about half that of a 10K.

2. See Joshu's post about his experiment comparing DEs to SEs

3. The best rule of thumb I have seen for "how much" light you need for SPS and clams is that you need 100 watts/sq. ft. I have 91 watts/sq. ft. on my SPS tank and I don't feel like I have enough, but its adequate.

4. Output is often effected by the age of bulbs.

5. Remember that light intensity decreases with the square of distance. That means that intensity decreases more rapidly the farther away from the bulb you are. Take a look at how high your bulbs are, and how deep your tank is with that in mind.

[RobertG]

3. The best rule of thumb I have seen for "how much" light you need for SPS and clams is that you need 100 watts/sq. ft. I have 91 watts/sq. ft. on my SPS tank and I don't feel like I have enough, but its adequate.

You are killing me, I am not even close to your rule of thumb!

I have 4 250W DE's & 4 54W T5's on the Actinic.

Not enough by the rule here. I can't handle any more power consumption. Oh well! >_< 76 ****.

[adamRS80]

Well I'll probably be going back to a 250w in some way or another. It looks like using a 10k with actinic supplementation is the way to go, which is what I have been trying to avoid just because of costs of replacement. I'd hate to spend like $125 every time I have to replace my bulbs but I guess I'm going to need to intensity of 10k at least. Thanks for everybodys help. Hopefully this will help bring my corals back to healty growth.

[Andrew]

I was trying to save money and keep my system simple and clean looking so I sold my old 250 system which was about 7" above the water and over a glass lid. This system is 5" above the surface with no lid.

Are you saying that there is no glass between the bulb and the water?
If so, you could be burning your corals from uv rays. All DE bulbs need to have glass between them and the water to block uv.

HTH

Andrew

[GaryP]

[Not enough by the rule here. I can't handle any more power consumption. Oh well! >_< 76 ****.

Well, with the depth of your tank I would have gone with 400 watt bulbs anyway. Your tank is a 215 isn't it?

[GaryP]

I sold my old 250 system which was about 7" above the water and over a glass lid. This system is 5" above the surface with no lid.

Glass lids are an issue all unto themselves. You are cutting down light transmission, even if its clean. In addition there are heat issues with a lid. Do you still have the lid on the tank? I don't remember if you said in your previous posts.

[RobertG]

[Not enough by the rule here. I can't handle any more power consumption. Oh well! >_< 76 ****.

Well, with the depth of your tank I would have gone with 400 watt bulbs anyway. Your tank is a 215 isn't it?

Its a 240 96x24x24, I really like what my lights are doing. Just the thought of not meeting the rule of thumb theory kills me. :lol

[alton]

Of all the SPS corals I have seen in freinds tanks they keep them towards the top of the tank with 250 watt MH min. One thing I missed on this post was how deep is your tank? I think Tim hit the nail on the head with the 250 14k to 150 20k, try changing to 10k in the 150DE.

[adamRS80]

After much thought I'm considering selling everything and taking a break for a while. Are some of you guys are interested in some light deprived corals? I hope it doesn't seem like I'm making a rash decision, I acutally typed up a long list of everything and my reasons for selling about a month ago and just decided to stick with it a little longer. I just don't think I can afford to do anything with the lights right now and so tonight I'll probably post it all for sale unless I have a change of heart and decide to keep on trucking. We'll see. Thanks for everybody's advice, I would have to say with the response I've gotten and what I know about my tank, the lack of light has to be causing this issue so hopefully some of you can take my precious corals and give them what they need.

[adamRS80]

Joshua, I sent you a PM

[Tim Marvin]

http://www.marinedepot.com/aquarium_lig ... sp?CartId=

I'd try these if you can't get them cheaper from Greg at 360 ReefFarms.

[GaryP]

hah, not up to spec Robert, better get cracking. ;) Water clarity plays a huuuuge role as well. I'm sitting at about mid 80's in Gary's rule of thumb and I'm actually reducing my photoperiod this week down to 7 hours a day for the halides.

Like I said, I'm at 91 with my VHOs on and they are out of operation right now. I think the 100 is a best of all worlds scenario. I figured out Gator's ratio and its almost 250 watts/sq. ft.

[NaCl_H2O]

3. The best rule of thumb I have seen for "how much" light you need for SPS and clams is that you need 100 watts/sq. ft.

Gary, measuring SqFt in which two directions, length x height?

Example: My 215g SPS is 72x24x29, so 72x29 = 14.5 SqFt = 1450 watts?
I have 3x400w 10Ks + 2x160w VHO Actinics = 1520w

So I am happy???????

[GaryP]

I am referring to the surface area of the water, so in your case that's 72 X 24" inches = 12 sq. ft.

1520 watts/12 sq. ft. = 126.6 watts/sq. ft.

Can a math major keep up with HS geometry and algebra? I didn't even have to use diffyQ. :)

[NaCl_H2O]

Actually, that would be 126.6667 watts/sq.ft. ;)

[matt]

Try changing the bulb to the XM (actually XDE, I guess) 10k and see if that helps. That's the cheapest and easiest thing to try first. Don't worry about actinic supplementation; that's mostly for color correction anyway. The 10k bulb will produce way more PAR (or PPFD, whatever you want to use as light intensity useful to photosynthesis) and that's what your corals need for health.

I still bet there's a water quality issue, though. Unless your new sand bed is heavily stocked with worms and other detrivores, probably it's not really functioning as a deep sand bed. When you put sensitive corals in this situation, subtle degrading of the water quality over time due to the new sand bed not being able to "keep up" with the bio-activity in a stocked tank can take place. I'm pretty sure that's what happened to my old tank after I moved it and replaced a lot of the sand bed, and eventually most of my corals died. It wasn't until I bought 100 bristleworms and all sorts of microverts from inland that the system turned around. In the old location, with a mature live sand bed that developed along with the corals in the tank, everything was healthy.

That's my theory, anyway. I have no proof for it, but it was really the best explanation.

[adamRS80]

Thanks Matt. I'm going to do something about the light, either replace the bulb with a 10k or get a 250w light and get back to where I was, and then I'll get to work on my sand bed.