What is happening to my gbtas????

[blumarlin]

I have 2 gbtas & 2 rbtas. (2 xtras due to splits). They have been thriving in the tank for close to a year now. Changed the lights after about 11 mos in Jan (48" Nova Extreme 4x54, T5HO w/ 4 luner lights). No problem, they were all fat & happily settled until about 10 days ago.

I have been fighting a cyno & hair alge for a few weeks now. I had been using a tap water ion-exchange resion chamber, which I thought was ro/di, but is only ro. I invested into to a ro/di chamber, float swich & covered plastic garbage can. It is so nice just dipping out a bucket of water when you need it.

Anyway, my btas have moved under the rocks where they reside. They used to do this @ nite & be streched out all full & fat during the day. The rbtas are comming back out, but only 1/2 way & still look healthy & will take food. The gbtas (on other sides of the tank) look horrible (from what I can see of them). They are all schrivled up, have a purplish color & some of their tips look white w/ a hole in them. (I will try to get a pic tomorrow, but they are hard to see). It seems as though maybe something is biting them? But, why are the rbtas ok? I have broken out the flash light several times in the am for the past 2 nights & see nothing bothering them.

I did a 20% water change 2 days ago. I usually do a 10% every 10 days.
I tested my water today: phosphates: 0 (added carbon ect)
Nitrates: 0
Ammonia: 0
Ph: norm
Alk: slightly low
Cal:360 (normally it is between 420 &
460??)
Temp: 78.9-80
Specific Gravity: 1.023 (usually 1.026...
could this be part of the problem?
Everyting else in the tank is doing great: mushrooms, feather dusters, snails, crabs, frogspawn, gsp, candycains, leathers, fish ect.
I really didnt want so many nems, but now I am attached to them & dont want to loose any of them.
Please, any advice will be greatly appreciated.

 

[Toddrtrex]

Of course the pictures will help.

When I kept BTAs I always had my salinity at 1.026, but yours isn't that low. When did it drop and how quickly.

How long have you been using the RO/DI water?

What fish do you have in the tank?

 

[blumarlin]

I will admit, I havent checked my prams in a couple of months, so I cant tell u when it dropped (I am feeling so guilty now, I used to do it regioulsy once a week). Although, I have always done my water changes, which went from every 7 days to every 10 days.
In the am I will top off w/ saltwater, but like u , I really dont think the drop in salanity would make this much of a drastic differance in their behavior. It is now 1:45 in the am, did a flashlight tank check, nothing bothering them. I am at a lose here & dont know what to do, but I do know that they are so unhappy.
I started the ro/di a few days ago, still fighting the cyno & hair alge, but it is getting better. But that really shouldnt effect my nems? I know it will take a few weeks b4 I finally beat the cyno, but does that affect the nems?
I have crabs in the tank, but only see them muching on the algee. I blamed my sallylight foot for taking a bite out of my coral beauty, but have seen my clarki & coral beauty fighting & coral is the instigator. Go figure!

The fish in my tank: coral beauty, clarki, maroon clown, yellow tang, regal tang, 6 line wrass & a yellow watchman gobie.

I also have a purple hitch hicher crab (been in there for months), the sally, snails, a couple of red legged hermits, 2 tiny emerald crabs & 6 teeny tiny hermits that were added to the tank last week to work on the algee (& by the way, are doing a great job)

So, I cant really blame my nems problem on the new guys, bcuz the problem started b4 them.

I just dont get it!!! I really hope someone can help me .