Zoas dying

[tcwoodrn]

I have a frag or two of zoas that are dying , and I was hoping someone could shed some light on the problem. Over the past two weeks I've had a couple frags stop opening up and gradually shrivel up and die. There seems to be no rhyme or reason, and its two frags at completly different sides of the tank with many other zoas between them. I inspected them for zoa-pox and that's negative. About a month ago I found what I thought to be a zoa-eating nudi on a frag. I dipped all the zoas and found a few others with no eggs on any polys. I have not seen any others in a few weeks (I check constantly at night and have test dipped a few polys to see if any come off). My tank parameters are fine except my salinity is always high (1.026-1.027) and I struggle to get it down because of the massive evaporation I get from a topless biocube.

Does this sound like a nudi issue? Maybe a salinity issue? Is it just a few polys not surviving that's normal? I mean they look 100% good one day then the next day they don't open and a week later they're dead. ***?

 

[650-IS350]

My salinity fluctuates from 1.024-1.025 where I usually have it at to 1.027 no issue. Whats your KH and pH at? Flow? lighting ? and TEMP ?

 

[tcwoodrn]

8.3 ph, they get high flow, temp is 76-77, lighting is a 150w 14k HQI with 2 65w actinics. (Aqualight Pro). This is all in a 29g biocube. Unknown KH

 

[650-IS350]

Check you KH I had mine go all the way up to high 20's lost a lot of polyps and other coral.

 

[tcwoodrn]

I honestly have no idea what KH is. I suck.

 

[650-IS350]

Carbonate hardness, or Carbonate alkalinity is a measure of the alkalinity of water caused by the presence of carbonate (CO32-) and bicarbonate (HCO3-) ions. It is usually expressed either as parts per million (ppm or mg/L), or in degrees KH (from the German "Karbonathärte"). One German degree of carbonate hardness is equivalent to about 17.848 milligrams of calcium carbonate (CaCO3) per litre of water (17.848 ppm). Both measurements (mg/L or KH) are usually expressed "as CaCO3" â€"œ meaning the concentration of carbonate expressed as if calcium carbonate was the sole source of carbonate ions. Bicarbonate ions only contribute half as much carbonate hardness as carbonate ions, so bicarbonates that are present in the water are converted to an equivalent concentration of carbonates when determining KH. For example:


An aqueous solution containing 120 mg NaHCO3 (baking soda) per litre of water will contain 1.4285 mmol/L of bicarbonate, since the molar mass of baking soda is 84.007 g/mol. This is equivalent in carbonate hardness to a solution containing 0.71423 mmol/L of carbonate, or 71.485 mg/L of calcium carbonate (molar mass 100.09 g/mol). Since one degree KH = 17.848 mg/L CaCO3, this solution has a KH of 4.0052 degrees.


Carbonate hardness supplements non-carbonate (a.k.a "permanent") hardness where hard ions are associated with anions such as Chloride that do not precipitate out of solution when heated.


Carbonate hardness is removed from water through the process of softening. Softening can be achieved by adding lime in the form of Ca(OH)2, which reacts first with CO2 to form calcium carbonate precipitate, reacts next with multi-valent cations to remove carbonate hardness, then reacts with anions to replace the non-carbonate hardness due to multi-valent cations with non-carbonate hardness due to calcium. The process requires recarbonation through the addition of carbon dioxide to lower the pH which is raised during the initial softening process.

 

[evoracer]

I started to have polyps recede and/or shrink in my prop system, turned out I had my main pump leaking voltage into the water. Found it when I had a cut on my finger and reached into the tank, felt that zing!

 

[tcwoodrn]

Would high Phosphate explain my problems? I do noticed some rust-like algae forming on my egg-crate frag rack (it bubbles an awful lot). One of the frags that had the rusty stuff on it cleared right up when I moved it off the frag rack. I do not have a phosphate test kit yet.

 

[650-IS350]

I don't know, phos not good though for SPS. I just started running a phosphate reactor though. seeing better results.