PDA

View Full Version : stn on acros?



jjoos99
09-03-2010, 09:39 PM
Something is going on in my tank that i am getting very nervous over. Several of my corals are starting to stn from the base upwards. When I test the water the only problem area is an elevated alk level. I just tested it and it was at 11.2. Most all of the corals are not looking like they should with decreased pe. I wouldnt think it would be the leds lights that I have switched to since it is stn'ing from the base up. I just discovered I had my temp controller programmed wrong and the heater hasnt been working but I have never seen the tank below 79. My sal. is at 1.025 and I havent experienced any algae issues so I dont think it would be a high nutrient level. Can too clean of water possible cause this? I have noticed my skimmer isnt pulling out what it has been doing in the past. Even the caps are bleaching on some of the edges and a few spots in the middle of them plus the colors have faded out. My millis have alittle bit of stn but nothing like the acros. I wonder if I shouldnt slow down the skimmer or maybe cut the gfo reactor?
thanks

mrfish183
09-04-2010, 07:08 AM
High alkalinity usually isn't a problem. However, rapid changes in alkalinity are known to be problematic for SPS. Do you typically have high alkalinity? Are you dosing carbon? Carbon dosing combined w/high alkalinity is known to cause tip burning but not STN. I'd also watch the GFO w/high alkalinity. GFO will cause local precipitation of CaCO3, which could be causing alk swings. It sounds like all your coral are being effected so I wouldn't expect a pest like AEFW, which is acro specific.

jjoos99
09-04-2010, 08:12 AM
I use to use a small amount of carbon in a gfo reactor but I ran out and never replaced it. I shut off the flow to my gfo reactor and turned off one of my recirc. pumps to my skimmer last night as well as shutting down 1/3rd of my led lighting. I dont like to make that many changes at once but I am getting a little desperate. I have 2 of my nicest acros that the stn has worked it's way up the base and isnt far from starting on the branches. The highest that I tested my alk at was 13.6. It currently is at 11.2 and hasnt dropped much in the last week or so. My ph was at 8.05 last night before the lights went out.
thanks
jeff

jdl513
09-04-2010, 10:07 AM
Jeff,

Have you checked the pH/Alk in the morning before your lights come on?
How old is your aragonite sand/gravel base and live rock?

I have been adding some fresh aragonite sand to my display here of late trying to bolster the buffering capacity.
Holding the fort so to speak until I move and which point I will be getting all new aragonite base and rock.

If your base is getting up there in years it may not be able to buffer the day/night swings like it used too.

Complete shot in the dark.

jjoos99
09-04-2010, 07:05 PM
I actually havent checked the level first thing in the mourning. I run crushed coral in the main tank which is only maybe 1in thick. I have a remote sand bed in my sump that is maybe 4 years old. I do get alot of red slime algae growth in the sump but none in the display tank. I have the sump lit with 2 spiral 65 watt florescent bulbs which might be causing the algae.
jeff

jdl513
09-04-2010, 08:20 PM
*****Disclaimer*****
I am sure there are other more experienced hobbyist who can say I am crazy, so please don't focus too much on just my hypothesis. If I am crazy I hope they speak up as I would want to know where I am in error.

On to the pH day/night swing hypothesis:

It might be worthwhile to test in the morning before your lights come on just incase your systems natural buffering capacity has been exhausted.

Increased organic acids from decay during the night...pH drops...buffered by carbonates.

It should be easy enough to prove or disprove by testing pH right before the lights go out then first thing in the morning. If pH is different in the morning then I would replace some of the crushed coral or sand bed with fresh crushed coral or aragonite sand or to recharge the buffering capacity.

Hopefully that is all it is as it's easy to remedy, but it is just shot in the dark.

As for the red slime I would bet it's the bulbs.
Not sure if the red slime is adding to or causing the problem, but it could not hurt to replace the bulbs to eliminate that variable.

aquavista99
09-05-2010, 11:11 PM
Jeff,

If your water parameters are in check and you are keeping up with wkly water changes, then I would highly recommend you start removing some of your acros that are starting to bleach from the base up and investigate for possible pests, namely, check for acropora eating flat worms, which are difficult to see by the naked eye while the corals are underwater. If you remove some of the corals out of the water for a few minutes and allow them to almost dry out, you will be able to see AEFWs moving around, if present. Usually when everything else is going well (ie, high flow, high lights, over skimming, water parameters okay), then pests could be present and the cause of your problems.

As for your montipora corals starting to bleach, they will be the first to react to an Alk spike or nutrient spike, but usually most SPS can thrive under elevated Alk levels...but an Alk spike is a different story. I would also closely examine your montipora corals for possible pests as well, namely, look for Montipora Eating Nudibranchs.

mrfish183
09-06-2010, 02:28 AM
Are you sure your alk test kit is correct? A pH of 8.05 at an alkalinity of 11.2 dKh implies excessive CO2 or very high nitrate. I'd guess your pH drops to 7.75 to 7.85 at night. I don't think this low pH is the source of your problem with two condtionals. Conditional #1, you need to keep your alk high and keep the Ca balanced with the higher alk (there are online calculators for this). Conditional #2, your nitrates are OK.

Perhaps someone w/AEFW and MEN could bring affected species to one of the meetings so we all could see examples of these things.

Kurt
09-06-2010, 09:05 AM
I have found that STN from the base up in many occasions can be directly linked to a lack of flow. As corals mature and branch out, those area that used to receive good flow, no longer do. If you have a couple extra powerheads you could drop them in. Even if you have to stick them on the front glass for a short time to see if you can randomize the flow a bit. You may be surprised at the results.

Pests should be easy to identify if you have them and can either be ruled in or out rather quickly. I personally would not jump to a chemical problem or solution. Chemical mishaps often show as RTN in a very fast way.

Go for the simple wins first!

Good Luck --Kurt

aquavista99
09-06-2010, 11:31 AM
Perhaps someone w/AEFW and MEN could bring affected species to one of the meetings so we all could see examples of these things.

If you are interested in learning more about these pests, check out the attached articles below.

The Montipora Eating Nudibranch
http://www.qualitymarine.com/News/Featu ... 9/11/06%29 (http://www.qualitymarine.com/News/Feature-Articles/The-Montipora-Eating-Nudibranch-%2809/11/06%29)

Acropora Eating Flatworms
http://www.melevsreef.com/aefw.html

1badbrd
09-06-2010, 03:11 PM
my vote is check flow. I had that happen to one of my best corals and after i moved fragged it up and moved it in fear of the STN all pieces lived and grew back on their bases so...... i ruled out all other options and pointed blame to not liking the placement and flow .

jjoos99
09-06-2010, 08:10 PM
I have a 180 gallon tank with 2 mp40s along with my return pump. I might start to look for another vortech. I will check for pests but the only coral I have added in the last year or so was a piece or ora plum crazy back in June and that coral is in perfect shape with no stn at all. I would think if it had introduced pests it would have been dead by now. I did check my pm in the mourning and it tested at about 7.89. i have had my co2 shut down for a good week now to try and get my alk down into the 9-10 range. i should probably start it back up slowly for now.
thanks for all the advise
jeff

mrfish183
09-07-2010, 08:53 PM
When I suggested high CO2, I didn't mean the reactor's CO2. I meant your ambient CO2 levels in your house are likely high. For normal seawater and atmospheric CO2 levels, an alkalinity of 11.2 should give a pH of 8.43 while you are measuring between 7.91 and 8.05. This implies an ambient CO2 level of 1000 ppm in your house (assuming perfect aeration), which is 3X atmospheric. As such, I would be very careful lowering alkalinity in an already low pH/high CO2 environment. The key to calcification is maintaining Ca/alk supersaturation. CaCO3 is more soluble at low pH and thus it is more difficult to achieve coral calcification & growth at low pH. You can only counteract this by increasing the alkalinity and Ca level. Mg is also important because it stabilizes the supersaturation of Ca.

I know none of this addresses your original problem .... but lowering alk in your situation would make things worse ... but don't change anything quickly ... especially alkalinity up or down for SPS!

Reef'd Up
09-08-2010, 07:25 PM
If you keep track on Reef Central and local forums, you'll find an increase around August in the amount of people posting about RTN & STN in their Acroporas. I too experience it this time of year. Not saying the STN/RTN is related to the time of the year for everyone...just saying if you look back at general trends, there seems to be a larger amount of people posting about it this time of year. So, assuming it's time-of-year related, it could be a few things this time of year:

A/C running more during the day...windows open at night - high CO2 levels in the house then dropping at night
Temp swings more than the rest of the year
Or, it could possibly have something to do with the yearly spawning event of corals. There's not a whole lot of understanding how corals know to spawn at the same time each year, but there is some evidence for gravitational pull. Since corals don't spawn in our tanks for the most part, there could be a stressor to them regardless at this time of the year.

I know none of that helped you solve your problem, but you're in the same boat with a lot of people who just have recurring STN/RTN this time of the year with no direct cause. (The above were only my theories relating to this time of the year. I haven't seen any official studies or anything done on why this occurs...or even if it's common knowledge it's more common this time of year.)

jjoos99
09-09-2010, 08:21 PM
what is the cause of higher co2 levels within a home? My tank is in my basement and the temp stays pretty stable with my controller. It never gets above 79.5 deg. How do you address a high co2 level within a home? The corals have seemed to stop any more recession but my pe still isnt close to what it use to be. I have been adding mg supplement, 6 tbs per day. I will test and see if I have been able to raise it above the 1200 level. Niki that is an interesting observation.
thanks
jeff

1badbrd
09-09-2010, 09:08 PM
I have a 180 gallon tank with 2 mp40s along with my return pump. I might start to look for another vortech not stating need more flow maybe too mich to a certain area that the coral didnt like.

My case was the flow was too much to a cartain area and it wasnt until i moved the coral a little further away from teh source of flow it looked much better and started to get its growth back

Reef'd Up
09-10-2010, 05:18 AM
High CO2 levels in homes is usually due to newer homes build construction. Newer houses are usually better insulated, so CO2 just builds up within the house. I'm not really sure how much fresh air HVAC systems pull into houses, but I do know newer houses usually have a CO2 problem with their tanks. STN/RTN seems to occur more toward the end of summer rather than the middle of it. Not sure why. One way people cope with this is to run an airpump line outside their house and pump fresh outside air into their tanks. It helps keep the pH from swinging as much. Mrfish sounds like he's better versed with how house pH will affect your tank.

Are you diluting the mag supplement before adding it to your tank? Some corals may become irritated from direct concentrated contact with mag.

jjoos99
09-10-2010, 07:17 PM
My home is about 2 1/2 years old. I am sure there isnt alot of air movement in the basement. I dont have any fresh air intakes or outlets in the basement for my heat/cooling system. I am adding the mg into my skimmer tub so it mixes with quite a bit of water before it ever makes it back to the main tank. I ordered a new ph probe for my controller so I will be able to get a on the spot measurement of my ph. I have to use my ph pen right now.

mrfish183
09-10-2010, 08:53 PM
Iím not sure Iím an expert but I certainly have lots of experience w/low pH and high CO2. Reef'd Up did an excellent job in explaining the source of high indoor CO2. In addition to new homes having issues, you can also have issues if you have gas appliances combined w/insufficient venting. Also, if you operate a calcium reactor, then your pH will be lower due to higher absorbed CO2. In my experience, a calcium reactor will lower pH by about 0.1 unit compared to a non-calcium reactor system operating at the same alk and ambient CO2 level. The high CO2 can be counteracted by numerous means. One can continuously exchange air with the outside using a bath fan, a HVAC ventilator, open windows, or most preferably your skimmer drawing outside air. One can also remove CO2 with chaeto. The effects of high CO2 can be counteracted with high alkalinity, kalkwasser dosing, and/or soda ash 2-part dosing.

My skimmer pulls ~2,000 l/hr of air from the outside, which results in a pH increase of about 0.15. When I dosed kalk, it would elevate pH anywhere from 0.05 to 0.20 depending upon the state of the kalk. Soda ash two part has moved my pH up another 0.15. I no longer use a calcium reactor or kalk reactor. I only use the two-part. My pH now varies from ~8.00 to ~8.25 at an alk of 10, which is much better than the 7.60 to 7.85 I used to observe.

It is too soon for me to say whether my corals look any better. My corals grew at a reasonable rate even at the low pH consistent w/otherís observations. Most successful SPS keepers still utilize calcium reactors, which depress pH to various extents depending upon aeration. However, most of these same people also operate at the higher end of alk & cal. It is the general consensus that high CO2 isnít a problem as long as alk, ca, and mg are maintained on the high end of things.

There is one problem I recently encountered w/operating at the high end of alk due to elevated CO2. As the weather has become cooler, my wife has started opening our windows to let in fresh air. On these days, my pH shoots way up (8.45). If the pH went much higher than this, then Iíd risk spontaneous CaCO3 precipiation and a rapid alk drop! I donít think this will be a problem as long as I keep the alk below 11 and mag above 1250.

jjoos99
09-10-2010, 09:16 PM
How far might i be able to run my skimmer intake hoses without affecting the air draw? That might be the easiest route to take. My skimmer is currently close to an outside wall in my basement and I should be able to drill a hole in the band board and run the hoses out. I would guess you would probably want to increase the size of the hose from the skimmer to the outside?
thanks
jeff

trish&dave
09-14-2010, 02:21 PM
Just be careful the hose is not close to any exhaust fans from inside the house (read that somewhere) and make sure if it is close to your garden or lawn that pesticides are not sprayed close to the intake hose. Just a couple things I have read, but thought I would bring up for the more experienced.

mrfish183
09-14-2010, 06:59 PM
Just be careful the hose is not close to any exhaust fans from inside the house (read that somewhere) and make sure if it is close to your garden or lawn that pesticides are not sprayed close to the intake hose. Just a couple things I have read, but thought I would bring up for the more experienced.

I found this out the hard way a couple months ago. I had just purchased a controller for my aquarium and this let me monitor my pH continuously. After a couple weeks, I plotted pH versus time and noticed that my pH dipped 0.2 points at 7:35am EVERY day. I investigated further and discoverd this dip always occurred after I took my shower in the morning. Closer examination revealed a dip occurred everytime anybody used hot water. I then traced the pH dips to my forced air water heater. The outlet for my forced air water heater was pointed directly toward my skimmer inlet on the outside of my house. Even though the two were separated by six feet, the CO2 from the combustion was enough to drop my pH within 10 minutes by 0.2 points! I changed the direction of my water heater outlet and the problem was resolved.

My skimmer is about 30' from the exterior supply. The skimmer was supplied with 1/2" ID silicone tubing but I increased this to 1" ID PVC. The airflow has been unaffected. I do have to clean the volute more often in the winter due to excessive evaporation caused by the low relative humidity air. Still, this is the best way to quickly remove excess CO2. They do make special CO2 scavengers for protein skimmer now. They contain SCUBA rebreather material that absorbs CO2 from the air entering the skimmer. It is an expensive option. I opted for the cheaper approach and a switch to two part.

L8-NiTe
09-24-2010, 09:12 AM
Check for red bugs.They will be tiny and usually look more yellow then red.Its hard to see them on any coral that is red/orange/yellow.They will usually kill the coral off from the bottom up or underneath branches out of site.

jjoos99
09-24-2010, 05:05 PM
I have seen alot of improvement in my corals in the last couple of weeks. I noticed the stn has stopped and some of the color is coming back to the caps in the tank. I still have a decrease in pe on some of my corals but I think that will come back in time. I am thinking of adding another mp40w also. I believe that the increase in dosing of mag. and bringing down the alk some has contributed to the improvement. I did get a new ph probe and have been pretty steady at 8.05 during the day and maybe dropping just alittle during the night. I still need to route my skimmer hoses to the outside yet. I appreciate all of the help and support.
jeff