Need advice: weakening Corals

[starsky]

Tank is in apparently good condition...coralline algae doing well...2 ocellaris doing well also.

Salinity 1.024, temp is 80F, 65G RR, sump with Skimmer, 70 lbs of LR, 5 inches of DSB. Have 2 pieces of coral...Zoos and Star Polyphs. Other critters are 5 of each: Margarita and Astrea Snails, and zebra hermit crabs.

Tank sand and rock was migrated from original tank of 2 years. New setup running now for 8 weeks...coral has been in there for 4 weeks. They sit on rock 6 inches away from 110 watts of PC, 1 Actinic and 1 Daylight 7100k.

Only in the last week have I noticed SIGNIFICANTLY less extension in the Star Polyph...browning versus the original more pink color. Salinity was originally 1.028 but I've diffused salinity by adding and removing water as minor water changes of 2-3 gallons 3 times a week for the past 2 weeks. Don't know if this has anything to do with it. Have 1 Hagen 802 powerhead in there...odd because the zoos are doing great and seem to be growing.

Please advise. I am hoping it is not the water condition...or the crabs. Will post water conditions after work.

Thanks in advance.

 

[taikonaut]

>.... or the crabs....

Crab and other "stimulants" can make a star polyp colony retract for a few weeks (yes, weeks), and you only have less extension? Relax.

Oh, welcome to RDO!

 

[reefNewbie]

did you change lightning from the old setup to the new one? Once we see the tests we will have a better idea what the problem is.

 

[Anonymous]

What's your alk and Ph. You'd be suprised how much of a change in alk and Ph will alter the looks of your inverts.

 

[starsky]

Thanks for the replies:

So the retraction doesn't mean death? Thank god! I did get new bulbs before dropping in the coral. It is making a huge difference because I haven't seen coralline algae growth so nice for a while. PH is above 7...based on the test I do routinely...but in the low 7's I'd say. Do you think Salinity has anything to do with it?

 

[cdeakle]

YES!!!!!!

YOUR PH SHOULD BE BETWEEN 8.1 - 8.4!!!!!!

 

[melanotaenia1]

A ph of 7? That is deadly, get some buffer in there or a water change asap, I would think with that kind of DSB using aragonite you should have better ph levels, but another thing to consider, though ammonia and nitrites harm corals, a ph of under 8 is just as bad if not worse.

When you bring up the ph you should see some results as long as the corals have not taken too bad of a beating already by the lowered ph

Good Luck

 

[starsky]

ahh...the PH...

I have southdown sand...is that why my PH is sitting around the 7 level? I did do a 10% water change this weekend...but that wouldn't be helpful if the PH of the water is not 8 right?

 

[taikonaut]

Substrate (SD sand or glass marble) have very little, if not insignificant, effect on water pH, countrary to common beliefs.

The water change *was* helpful no matter what the pH was.

 

[cdeakle]

Raise that ph ASAP.

Please don't take this the wrong way, not trying to bash or be rude but shouldn't you have known the basics at least of what ph range your tank should be in before diving into corals let alone reefkeeping?

I would suggest that you brush up and do some reading. This forum has alot of good free reading to help you catch up. Please do so, we all here would love to see your tank thrive and your inhabitants happy.

 

[starsky]

definitely not taking offense to this. I don't know how PH could have moved so quickly down granted the coral did so well for 2-3 weeks. Thank you all for the advice. I am hoping this helps.

Will the PH drift cause any issues with the clowns?

 

[melanotaenia1]

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Will the PH drift cause any issues with the clowns?

Most likely if they have come through it this far they will survive, fish can sustain fluctuations in PH as long as they are not quick i.e. if your pH went from 8.3 to 7 over a period of weeks it would be more likely to be sustained by the fish. However, when bringing the pH back up do it very slowly so as to not shock the fish. I would not go about this by adding buffer or anything like that because it will probably kill the fish because of the shock. If you do small water changes with salt most likely the salt you use, if it is of any quality, should bring the pH to 8.3 upon mixing it with fresh water, regardless of what the pH of the freshwater is. The water change, therefore, will help since it is slowly bringing the pH up, and again, this is what you want to do, instead of shocking the fish and corals. It is sort of like when you get a fish from the store, their waste and breathing has caused a drop in the pH in the bag they are in, so adding water slowly to the bag helps to bring the pH to normal levels without killing the fish.

Clowns luckily are pretty hardy fish and more tolerant than most. Many marine fish will have a hard time surviving any pH under 8. I have noticed that if I do partial water changes on a regular basis with instant ocean my pH always stays around 8.3 with little buffer needed. But I also have aragonite sand which may help that number.

 

[starsky]

Thanks all...here are the water condition results:

PH: 7.8
Salinity: 1.024
Ammonia: <0.01
Alkalinity: 12
Nitrite: 0.05 mg/l
Nitrate: 5-10 mg/l

Used buffer and now PH is 8.2

Unfortunately I am thinking my star polyphs are lost...

 

[cdeakle]

a ph of 8.2 is good!