Tank on a downslope.... suggestions please

[Mac Inger]

My tank has been deteriorating for the past couple of months and i am not sure of the reason. Let me outline here my equipment and parameters then a history of what has been happening, hopefully somebody will see what i am missing.

Tank is an Elos 55g rimless, deltec apf600 skimmer, vortech for circulation, 250w Helios 20k DE 5 months old on a 9 hours/day photoperiod, Kalkwasser reactor with Miss Wages pickling lime and Korallin calcium reactor (i changed the media last week, it hadnt been changed in 5 months). I run a small 9 watt UV, carbon and phosban. Lately i have been running also polyfilter.

temp 79-80
Alk 9 (fasttest instant ocean), 11 Elos
Mag 1200 Elos
Ca 460 Elos
Copper 0 Api
Ammonia 0 salifert
Nitrate 10 Tetra, 5 Salifert
ph 8.1-8.2
salinity 35
Orp 350


The downslope started a couple of months ago. Some of my inverts started dying. Lost 2 shrimp and a couple of nassarius snails. Then i started loosing color on the sps and eventually came to the point where some sps were stn-ing from the tips and the base. Some other sps are still doing fine, although growth has ben stunned. My blue linckia star that i have had for 2 years now has lesions in its body.
Yesterday i dropped in 3 nassarius snails in the tank. They were active when i picked them up. This morning, one of them is almost paralyzed laying with his foot up in the air (i have seen this before with my other nassarius, a sort of lethargy).

In the meantime, several other corals and fish are doing just fine. What i have also noticed is that my sand (in some areas close to rock) has solidified. I run about half an inch of sand.

I know my parameters are not textbook perfect, but i doubt they would cause the paralyzing of a snail overnight. Some of the corals i had to give away i have had for over two years, including a massive purple monti which survived moves and kalk overdosing etc and was growing like a weed.

Another element that i saw accompanying this downslope was the lowering of my orp. I was running a steady 400 and somehow that started going down slowly to where i am now. I also was using SCRIPPS water for my water changes for the longest time with good results until the start of the decay. recently thinking that i might have hit on bad batches i changed to Torpic Marin Pro and have started doing religious weekly 5 gallon (10 percent) water changes.

At this point i am thinking either something was dropped somewhere in the tank, lead, iron, smth. Or the MsWages pickling lime batch i got was weird or the magnet of the Vortech (which is showing blisters) is leeching something in the water.




this is how it looked two months or so ago. Not anymore,...

 

[Philwd]

My first guess would be copper. I know of little else to induce such a fast response to inverts.

 

[Mac Inger]

i tested and it came out zero. I am also running polyfilter and it has not colored up. All is picking is organics. Im baffled too,...that nassarius snail is still alive but still upside down

 

[gillesec]

Could one of your fish be picking off the snails and other inverts?

 

[Mac Inger]

no,...i have watched them very carefully

 

[nattarbox]

I have no idea what it could be, the number of variables in this hobby are frustratingly vast. I hope you figure it out though, that is a beautiful tank.

 

[MikeTV1]

Are all of your test kits within expiration dates? And maybe sending a water sample off to one of the online testing centers is in order. Get a more complete test for those things we don't normally test for.

 

[Mac Inger]

Mike,..i was thinking about sending the water to be tested, but i havent heard good words about these companies on the chemistry forum. Has that changed....?

 

[MikeTV1]

Just tossing out thoughts.

Can't say I have heard good or bad on the testing companies but thought that if one of their reports showed something elevated enough to be dangerous, you could at least test for that one thing separately without forking out for a bunch of individual tests.

Is your PH tested with meter or titration? meter calibrated recently?

The sand clumping is what makes me curious more than anything. Seems like something "off" would affect invertebrates, but it would have to be "WAY" off to cause your sand clump.

Have you pulled a sample of the sand? Is it changing form or just "glued" together by something? i.e., sand changing or bacterial explosion in sand

 

[coralnut99]

The sand hardening is the only thing that caught my attention as well. With what's been going on, the reduced ORP would seem to be expected, but also a cause for concern. I remember reading threads where sand beds had hardened or clumped. For the life of me I can't remember the causes that were thrown out in the thread. It might be worth trying the search function early in the morning on this one.
Aside from that, in a relatively stable system, there can occur a simple chain of events that simply leads to where you are. I would imagine it possible for something bacterial or even chemical to have affected inverts and the deaths set off a chain of events.

 

[Mac Inger]

That is why i introduced the 3 new nassarius snails,...to see if they would put a dent in the areas of sand that are clumping, unfortunately they died overnight, which is crazy in itself.(Acclimation time on the new snails was 4 hours, drip).

I have a big Derasa clam and it is fine, i also have 2 other Nassarius from a long time ago and they are still alive, RBTA and elegance just peachy.

The sand just seems to have been glued together, especially in areas where it is not getting stirred by snails etc (edge of rocks).

My Ph is Aquacontroller 3 measured, and recently calibrated with fresh solution.


Here is what Randy says about the phenomenon : (my sand is neither new or my ph too high....8.2 max)


New sand and high pH seem to promote such issues.

There are two different theories about how sand beds solidify, and I am not sure which is correct (perhaps both). Such solidification most often happens in new aquaria.

The first possible explanation is simply that calcium carbonate is precipitating onto the sand grains, cementing them together. That would be promoted by high calcium, alkalinity, and especially pH (the higher it is, the more likely it is, but many sands are fine at pH values up to pH 8.5), and low magnesium. It would also be promoted by a lack of organisms stirring the sand, and a lack of a good coating of organics, phosphate, magnesium, and bacteria on the sand (for example, on new sand).

The second theory is that bacteria growing on the sand cement it together with organic or inorganic materials. Depending on what exactly was being deposited, that would be promoted by a lack of organisms stirring the sand, as well as the same factors above.

 

[Tylt33]

My tank is crashing too, slowly, like yours. I'm hoping to change things this weekend. What's your Phosphate at? I scanned but didn't see a measure of it. Phosphate has a nasty effect on corals, and can stress other organisms. I see that you run Phosban, when was the last time you changed it?

 

[Untamed12]

This is the nice thing about a small tank. Skip the small water changes and go directly to a significantly large water change.

I don't know what is going on in there, but when in doubt that is a pretty good fix. Dilutes what you might have too much of...and adds what you might have too little of.

Ensure your ammonia kit is new/current. IME, those kits yield really poor results as they get older.

 

[Mac Inger]

i Have changed phosban regularly. Tomorrow i will be doing another big water change. Still a waiting game at this point....

 

[Barney_Googles]

Calcium precipitation causing sand bed compaction and bacterial die off (The beneficial bacteria has been choked and a slow release of sulfides has degraded water quality). Your levels have been fluctuating as the tank has been in a constant state of cycle...just a theory.

 

[Mac Inger]

Barney,..thank you, sounds interesting.
Please elaborate,..why would i have calcium precipitation ? And what should i look for to verify if i am indeed having this precipitation.

 

[saveafish]

calcium precipitation That i noticed the most is where the KH raises and lowers with the PH. This is only while adding suger based CA. Like seachem complete and calcium. What I would do is do several water changes like 15g every day for 3-4 days gently stir a portion of the sand bed 10-15min befor the water change. and move to a different part of the sand bed each time.