Why Won't My Corals Open?

[Vibrant Orange Zoanthids]

Greetings Reef2Reef. I doubt this is an emergency (so I didn't post it to that thread), but I would like to fix the problem before it becomes serious. So I have a 35 gallon tank which I test and water change regularly. I change about 1/3 of the water every weekend, but I only have the basic test kit for Nitrates, Nitrites, Ammonia, and PH. 2 weeks ago my Acans decided to shrink on me. They used to be much larger and rounder than most Acans I have seen, but they became smaller and did not respond to food. I was busy at the time, but came more concerned once my prized half and half Acan responded the same way. I also have an Acanthophylia Deshayesiana which shrunk up as well. It still responds to feeding in the water, but it's tentacles are much shorter than usual. 2 days ago I panicked and preformed a change of over half the water in the tank, hoping that the problem would end there. It didn't. It is also worth noting that all of my other corals are in perfect shape. Zoans, Hammer, Jack-o-lantern, Montipora, Pipe Organ, ect. What could be causing my corals to be unhappy? (I have pictures coming, but my phone has been 'sending' for the last 10 minutes.)

 

[Brad Miller]

With a 1/3rd wc every week, you would thing your calcium and magnesium would be ok.
1. How old is the tank?
2. How long have you had the corals ?
3. What lighting are you using and how long per day ?

Pics would be nice too

 

[Vibrant Orange Zoanthids]

With a 1/3rd wc every week, you would thing your calcium and magnesium would be ok.
1. How old is the tank?
2. How long have you had the corals ?
3. What lighting are you using and how long per day ?

Pics would be nice too

Pics would be nice, but for the first time ever my email is struggling to send it.
1. 5-6 months
2. My first Acan 2 months, the second about 2 1/2 weeks. It was only open for about 3 days. Acanthophylia Deshayesiana 1 month.
3. 8 hours per day. 55W T5 PC Flourescent (10,000K/Actinic)

 

[Vibrant Orange Zoanthids]

With a 1/3rd wc every week, you would thing your calcium and magnesium would be ok.
1. How old is the tank?
2. How long have you had the corals ?
3. What lighting are you using and how long per day ?

Pics would be nice too

 

[Brad Miller]

Acans tend to shrink randomly, I think is part of the way they grow, but should open back up.
I see some sand on a few of them, this will irratate them and make them close up.
Critters walking on them will close them up too until they get used to them.
If there are on the sand....what is the depth of the light fixture in inches away from them ?

 

[SuncrestReef]

You said you have basic test kits, but didn't post your test results. In particular, I'd be curious so see:

1. Nitrates
2. Phosphates
3. Alkalinity
4. Calcium

My corals didn't open when my nitrates and phosphates were near zero. I now keep them at 4ppm and 0.05ppm respectively and the corals are much happier.

Next, corals like stability. If you're changing 1/3 of your water every week, have you confirmed that the new water matches the temperature, salinity, alkalinity, and calcium of the old water? 1/3 weekly is more than most people change. 20% monthly is more typical. If your new water is significantly different than the old water, you could be shocking the corals each week.

 

[GSnake]

You said you have basic test kits, but didn't post your test results. In particular, I'd be curious so see:

1. Nitrates
2. Phosphates
3. Alkalinity
4. Calcium

My corals didn't open when my nitrates and phosphates were near zero. I now keep them at 4ppm and 0.05ppm respectively and the corals are much happier.

Next, corals like stability. If you're changing 1/3 of your water every week, have you confirmed that the new water matches the temperature, salinity, alkalinity, and calcium of the old water? 1/3 weekly is more than most people change. 20% monthly is more typical. If your new water is significantly different than the old water, you could be shocking the corals each week.

im hoping to raise my nitrates as well. cut back on my chaeto refugium light time... my birdsnest and other SPS never grow.. and the Birds have been losing color. I just made a post in regards to this in the chemistry section. mayb I should have posted in this forum instead ><

 

[Vibrant Orange Zoanthids]

Acans tend to shrink randomly, I think is part of the way they grow, but should open back up.
I see some sand on a few of them, this will irratate them and make them close up.
Critters walking on them will close them up too until they get used to them.
If there are on the sand....what is the depth of the light fixture in inches away from them ?

They are usually without sand, and I clean them whenever I see any on them. I doubt that is the cause since I've monitored them rather closely. My other is not on the sand, and he closed at around the same time, so I doubt it's a growing thing. I'd say about 19 inches away from the top at maximum.

 

[Vibrant Orange Zoanthids]

You said you have basic test kits, but didn't post your test results. In particular, I'd be curious so see:

1. Nitrates
2. Phosphates
3. Alkalinity
4. Calcium

My corals didn't open when my nitrates and phosphates were near zero. I now keep them at 4ppm and 0.05ppm respectively and the corals are much happier.

Next, corals like stability. If you're changing 1/3 of your water every week, have you confirmed that the new water matches the temperature, salinity, alkalinity, and calcium of the old water? 1/3 weekly is more than most people change. 20% monthly is more typical. If your new water is significantly different than the old water, you could be shocking the corals each week.

I'll run a test right now. I don't have a calcium test kit at the moment. While it is possible that the corals are getting shocked by the new water, I get it from the same person who owns enormous several hundred gallon tanks of it. Too low is something I didn't consider. I usually try to keep nitrates low. If I had to guess from what you've given me, I believe low Nitrates are the cause. Temperature does tend to differ by a few degrees after I add in the new water, but this never lasts for more than a few hours at most. Salinity and Calcium stay constant with the changes. At least, that's what the store tells me. In the case that I have too low nitrates, what would you suggest I do?

 

[Auto-pilot]

If I were you I would check your nitrates, Phosphates, Alkalinity. Calcium is important but it seems like it is more forgiving than most. even if you think the parameters of the water are consistent it doesn't mean the parameters of your water is consistent. I would recommend more frequent smaller water changes. Even if I matched the parameters really closely and changes 50 gallons of water in my 100 gallon tank my corals would be mad for a while, it can be really stressful on corals. Stability is the key to this hobby, the more stable you can make your tank the better your corals will grow and thrive. Changing large amounts of water is a good way to make an unstable environment for your tank. large tanks are actually easier because its harder to swing parameters and make mistakes. Its hard to run a tank low on nutrient by changing water, I feel like its more common when people grow macro algae or dose carbon. If you do find your nutrients low you can feed heavy or actually dose nutrients. I dose nitrate sometimes because I tend to run out and have a high amount of phosphates

 

[SuncrestReef]

Salinity and Calcium stay constant with the changes. At least, that's what the store tells me. In the case that I have too low nitrates, what would you suggest I do?

I think you’re misunderstanding an important point...Regardless of the parameters of the new water you’re getting from the store being consistent week to week, the water in your tank changes over time as the corals take in nutrients and elements. If your Alk in the tank drifts down to 7.5 but the new water you’re putting in is at 9.5, then you’re shocking your corals. You should test your tank water and the new water to see how far apart the parameters are before just dumping it in.