Rbta changing color and shrinking

[levi83]

my rbtas have shrunk and changed color. Not bleaching. They have changed from red to bluish greenish reddish. They actually look darker.
Sp. gr. 1.026
Alk 8.5
Cal 430
Nitrates <5
Lighting hydra 26hd @60% 8 inches over the water. Pics of before and after

Tank is a 28 gallon nanocube with no fish

 

[jsker]

What are your settings on the Hydra light? %60 might be a tad to high. Are you direct feeding them with small food or bit of raw table shrimp?

 

[levi83]

60 from 11:30 until 7. Was feeding freeze dried krill twice a week until they stopped eating.

 

[Amoo]

More Zoos = darker nems, it really is that simple and not all that surprising to tell you the truth. If your light was too high you would be bleaching them and not darkening them.

 

[levi83]

But why would they shrink???

 

[Amoo]

How long have they not been eating, what else is in the tank and what is your method of algae control (have you been dosing anything etc?) since I see a bit of green algae in the back but you said you have no fish.

 

[levi83]

They haven't ate in over a week. The algae is from the krill they were eating. Only filtration is chaeto and live rock. No dosing. 5 gallon weekly water change.

 

[Amoo]

do you soak your krill in anything or feed it dry?

 

[Amoo]

One last question then I'll get to where I'm going here, I just don't want to stick my foot in my mouth before I feel I have proper information.

How long have you had them?

 

[levi83]

About a month. I didn't soak the food but did squeeze them in the tank before feeding so they were soft.

 

[levi83]

The only reason I'm asking for help is thatI have a 210 downstairs with no problems I'm thinking about moving that rock down into but I really want to leave it in my nano. I just don't want to wait until it's too late.

 

[Amoo]

Ok I'm going to just brain dump on you here for a minute or two and if something doesn't make sense or you need clarification just ask.

Much visible Alage, Chaeto doesn't seem to be out competing tank.

BTA tend to walk when they get mad, yours are staying put and shrinking. This is abnormal, for this particular species, but not for most other kinds of nems.

Darking Zoos is to be expected with proper lighting, which would explain why they aren't moving. That said your MAX photo period may be lasting too long as in you might need a higher ramp and a shorter max, ie closer to 4 hours.

It seems odd that ALL 3 stopped eating at the exact same time after eating successfully for a few weeks. This leads me to think something happened in the things that are common to them all ie the food source or in the tank. Something sprayed into the house that drifted into the tank...etc. Maybe a bag of Carbon for a week could help here.

Something may have made them sick and it is spreading, but would expect much drooping and mad nems or at a minimum walking because of BTA.

---

So yeah, the darkening tells me your light strength is not a bad thing, the odd thing here is typically if the photo period was too long they would just get up and move which yours aren't doing for some reason. I would definitely shorten the photo period and think back and look around and see if something in the tank is off or changed. Be it flow pattern...etc.

 

[levi83]

Thanks for the idea. I'll try carbon and shorten photo period. They came out of a tank with 1 radion per foot but I don't know about his photo period. They came from 1 and split into 7 from the guy I got them from. He never fed them and I did, so that was the first true feeding they got. I'll give it a shot.

 

[levi83]

They haven't walked at all

 

[Amoo]

Yeah, if you watch the latest BRS video about the Radions or really any of their lighting related ones, one of the biggest things I take away from them is how much PAR changes based on mounting height. So honestly 1 radion per foot could mean literally anything. Yours are in a 28g biocube which means I believe they're sitting in a tank approximately 18 inches tall and I would guestimate they are about 10-12 inches from the waterline and your lights are mounted 8 inches from the water height which means your spread should be pretty decent at that depth (fwiw I personally always run my lights much higher but I don't feel that is relevant to this conversation and is something else we could get into privately or in a different thread). Either way if you were blasting them with light that was too bright they would most certainly be losing color, so the spectrum of light they are getting appears to be spot on. Now I do change my lighting height based on the depth of my tank so I run lights much higher on a 12" tall tank then I do an 18" and a 24". I do this for the reasons they show in the videos as you want even light spread at the levels you're concerned about. If it was me personally I would try halfing my CW max to like 25ish along with the other changes and see how they react. If you're unhappy with the way the tank looks at that color you can always increase your red and green a bit to get the "whiter" look you want.

Also just as an example of photo period and nothing else, this is how I run my 26s but do keep in mind this is 18 inches off the water and for a 12 inch tank AND for H.Mags and not BTAs. The numbers on the left represent my peek lighting not where the line currently is. Again I don't think there is a thing wrong with the spectrum you are giving them.

 

[levi83]

Good info. I don't like the whiter look. I just run it during the day while I'm not home so the nems get the spectrum.

 

[Amoo]

yeah a without getting TOO far off topic, I personally look at the white as a personal preference slider more then a spectrum slider. Yes there is the small possibility that it will fill in a few gaps of what you aren't getting from your B,V,G & R, but with most of the higher end lights with full spectrum lighting I find the CW to be unnecessary and more of a person by person thing. Now there are probably people in the lighting forum who would disagree with me, but if you're already covering the the full spectrum once, the white just adds even more of what you are mostly already covering. As always YMMV

 

[azreeftank]

Freeze Died Krill is like you and me only eating potato chips exclusively. If you don't soak them in vitamins even worse. You should be using different frozen foods in their diet like shrimp, krill squid etc. Think about it what food in the ocean is freeze dried? I don't feed my tanks anything freeze dried but have in the past and it is only as a "snack" the main diet should be combination of frozen

 

[levi83]

I've read that before but I've had a deep water rbta nem for years that eats nothing but that and grows and splits very well. It's bigger than a basketball. Probably 15-18 inches across.

 

[drtrash]

So if light intensity is low the anemone would produce more zoos to supply more food and therefore darken so more intense light would lighten color less zoo's not bleaching just lighter color correct?