polyp extension?

[Bill Nye]

I have a bunch of sps frags in my tank and recently i've been noticing some have had really great PE but some have lost alot of PE for seemingly no reason. Even though they have little PE I am still getting growth.

My main hypothesis is this is from low nutrients. My tank has Undetectable nitrates and phosphates and I believe this may be ****ing off some of the acros? I have dosing 1/2 strength Aquaforest AEBV and Coral food and using Sponge power (1 drop every other day).

This week I also noticed that my skimmer has been acting strange which I'm assuming is also from low nutrients. It has been skimming inconsistently where sometimes the water level will be sitting at the appropriate level in the skimmer and its pulling thick foam but now it will sometimes increase the water level in the skimmer without me touching it and not be able to push any foam at all.

Is low nutrients a cause of poor PE? Its odd that only some acros are effected while others are fine. I have been dosing nutrients and feeding 2 times a day for about a month and a half and still I cant read any nitrate.

 

[jda]

Not really. Fish picking, super high flow and getting their needs met elsewhere are all reasons that acropora will not risk exposing their polyps too much.

I would not worry about PE at all. If you have none on all of your Milles, then I might worry about bit, but not about low nutrients, but more about a predator. Ocean has lower N and P than all of us do (at least those who don't go crazy with organic carbon).

Seriously, chasing PE yields no fruit. Neither does chasing nitrate when you have a highly functioning tank with lots of rock and sand... any kind of food or sodium nitrate that you all will just allow more anoxic bacteria to grow and you will end up back down at zero again.

In my same system, everything in the frag tank is super hairy, yet the stuff in the display has very little PE - same lights, same water.

Skimmer water level is likely something else. Are all of your venturis and pumps clean?

 

[Bill Nye]

Thank you for the response.

Its interesting that no mater how much I have increased dosing nutrients so far I've seen 0 increase in nitrate. Some of my sps are paler than I'd like so I am trying to increase it to darken their color. I have one mille and it has really good PE. My tank is a bare bottom 50 gallon breeder with 3 liters of matrix in my sump, I have 2 mp10s on 100 percent NTS mode and I only have 2 clownfish, a firefish and a blue chromis so picking isnt the issue. The 2 corals in question had really good PE previously in the same locations and now its rather poor.

I am going to clean out my skimmer tomorrow when I water change. Maybe it clogged since I dose kalk in the same area in the sump.

 

[jda]

I agree - it weird that you cannot get N up in a bare bottom tank. Perhaps your rock is super porous and doing the job along with the matrix. I dunno...

How are your lights? I have found that alk, calcium (not as much as alk) needs to be low if N and P are, but also light need to be as intense as possible.

 

[Bill Nye]

I agree - it weird that you cannot get N up in a bare bottom tank. Perhaps your rock is super porous and doing the job along with the matrix. I dunno...

How are your lights? I have found that alk, calcium (not as much as alk) needs to be low if N and P are, but also light need to be as intense as possible.

My lighting is a 6 bulb ATI sunpower that I hang about 6 inches above the top of the tank. I've been thinking of moving it up but only two of my corals are pale and the rest seem to be liking it.

My alk runs around ~7.7 using a red sea test. Whenever I use salifert it always comes out about .2 higher for some reason. I'm using a mix of pukani and reef saver so nothing special. I think the matrix might be more of the reason?

I am running about 4 tablespoons of BRS GFO in a reactor. I've decreased it two table spoons a month to see if phosphates would increase, should I just remove the reactor and see what happens?

 

[jda]

I would not do anything for two corals when the rest all look great. Everybody has two mad corals in their tank.

 

[Bill Nye]

Well great is not the world I would use there is room for improvement before they look like the tanks you see here on Reefcentral

Thanks for the help.

 

[Reefer40b]

I would not do anything for two corals when the rest all look great. Everybody has two mad corals in their tank.

Words of the wise right there :thumbsup:

 

[ca1ore]

Fish picking is a 'problem' in my tank. Same corals protected in the frag tank show far better PE. They don't grow any faster though.

 

[Pife]

Words of the wise right there :thumbsup:

Agreed.

 

[Bill Nye]

Well just was looking at the tank with the lights off and noticed one of the corals with bad PE started to STN from the base. Not sure what is causing this but very frustrating.

 

[Bill Nye]

I raised my sunpower from 6.5 inches over the tank to 7.5 inches. It seems like some of the corals are getting too much light. The STN seems almost like bleaching.

 

[jda]

Do you have pests? I know that everybody's initial reaction is "no way," but seriously check it out. Red bugs in particular can keep polyps in as well as stress corals into STN... not so much RTN.

In any case, this also could just be coincidence. There are a lot of nice tanks with nearly no PE.

 

[Bill Nye]

Thanks again jda.

I took the acro that was stning out and fragged it today so I had a chance to check it out really well. I did not see any AEFW or red bugs. The last couple of nights ive been using a high powered LED flash light to observe the two corals that had bad PE and couldn't see anything suspicious. I always use bayer when I add frags but its possible something slipped by. I'm not sure how fast these pests spread but as I said my other corals have good PE.

As far as the coral goes, the tissue was rather thin and very pale in color on the side which got more light. It was hard to tell from my view in front of the glass because the front portion was shaded and it was the back region getting exposed to the light. I am wondering if adding sponge power, build and using a filter sock has increased the clarity of my water which in turned stressed some of the weaker coral?

I was doing some poking around on the net and it seems like corals in low nutrient environments are more sensitive to higher amounts of light but maybe that is just anecdotal.

 

[jda]

You probably don't have any red bugs, but worth a look. Mine always like Valida and smooth skinned stuff more than the hairy ones and did not bother all of the acropora, but I only had them once before I knew (even though I did know) to be good about where i got stuff and dipping. Look for them in the shadows near the polyps on the undersides of your colonies.

How is your alk? Alk needs to be low if you nutrients are low (like NSW levels) or else tissue can get thin and soft and tips can even suffer.

 

[nashorn]

Well just was looking at the tank with the lights off and noticed one of the corals with bad PE started to STN from the base. Not sure what is causing this but very frustrating.

Check your water Q
Especially salinity
I was a dummy and had a few rtn when it went down to 1.20
but others had great color and PE

 

[slavetonet]

You are keeping water. Not keeping corals.
Incorrect water chemistry is most likely your source of issue that cause the corals to RTN or STN.

 

[Bill Nye]

I tested all my water parameters on Sunday here are my results.

Salinity - 1.025
NO3 - 0
PO4 - .02
Alk - ~7.8
Ca - 440
Mag - 1440
K - 380

The only one that could be suspect is salinity since I've had my calibration fluid for about 2 years. Not sure if evaporation could have messed with its salinity level but otherwise everything seems fine.

 

[slavetonet]

I tested all my water parameters on Sunday here are my results.

Salinity - 1.025
NO3 - 0
PO4 - .02
Alk - ~7.8
Ca - 440
Mag - 1440
K - 380

The only one that could be suspect is salinity since I've had my calibration fluid for about 2 years. Not sure if evaporation could have messed with its salinity level but otherwise everything seems fine.

Those parameters are too general. It doesn't tell me much at all.
You are having issues because of other elements that you aren't currently test for.

The notion of keeping it like NSW is like sampling the left over of "All you can eat buffets". :debi:

 

[Bill Nye]

Those parameters are too general. It doesn't tell me much at all.
You are having issues because of other elements that you aren't currently test for.

The notion of keeping it like NSW is like sampling the left over of "All you can eat buffets". :debi:

So what do you suggest?