Overnight RTN help

[xanthurum]

I have a 34 cube with small sump and have had some issues with overnight RTN. Hoping someone can help with a cause so I can get a solution. I am thinking Alk swings after lights out.

Gen 2 Radion for lighting
Lots of flow from 2 powerheads comes to around 1000 GPH and return pump of 550 GPH
Ammo 0
Trite 0
Trate 2ppm
Phosphate .50
PH 8.2
Cal 420-450 fluctuation between WC
Mag 1300-1400 between WC
Alk 9
Dont know what it is at night

No skimmer but do 5 gallon WC each friday and run carbon one week a month. No fish just corals. Some SPS doing great like monti and stylo. Some acros doing so so and some RTN but not completely. 1 Milli did another has not, the one that did still has some polyps alive so it didnt completely die.

 

[MrReef101]

Same area. Or different? (The two millis)

 

[xanthurum]

Opposite sides of the tank but both at same height. Also the corals seem to try and even at times do have new growth during the day only to battle the die off at night. The Mille RTN'd well over 2 weeks ago but is regrowing over thw skeleton. I have a birdsnest that has lost tissue but growing great and has nice PE and I have a small frag of the same nest and it is doing great with no signs of any problems. Its strange that thy RTN and then stop and heal up only to RTN days later on the growth they just put on.

 

[triggreef]

I find it interesting that they stopped the TN and began healing in the first place. I've had only a couple acros STN and it was a slow process over the course of a few days. Tried everything I could to stop it but it just kept going. Tried glueing above the tissue, fragging pieces, etc and it just kept going, all while the STN'ing coral kept great PE. And while other acros in the same tank are still doing great. My parameters are pretty rock solid so I have no idea why that happened either. One of them was a tri-color that had encrusted off the plug and onto the rocks about an inch. New branches started, and then bang, death.

Sorry to hear your troubles. I have about 30 acros, but I can tell you if I lose another acro it will go un-replaced. monti and stylos will fill the void.

 

[xanthurum]

I find it strange as well, but that is what is going on. This morning I looked in and saw a tricolor with about 7 branches and fully encrusted plug RTN'd last night. It was fine last night but by the morning a large portion of the plug tissue was gone along with some tissue between branches. Yesterday it had decent PE but since it is still kinda new i didnt think much of it. I knew that by the time I got home it would probably be gone but the tissue loss did not get worse through the day??? In fact it is better than this morning. Same thing happend to another acro not far from the tricolor. It was a smaller frag with 3 branches, yesterday was perfect but 2 were dead this morning and now 1 is looking great.

 

[triggreef]

Has me thinking predator.

Do you have any blennies by any chance? I had one for a few months and then it became an acro hunter all of a sudden. Never would have guessed it if I didn't see it first hand.

 

[xanthurum]

No fish at all

 

[jackson6745]

No fish at all

Does this mean no feeding? Never a good idea to be fishless with SPS.

Is your po4 reading .5 or .05? If it's .5 (which I find hard to believe with no fish) that is extremely high.

Do you have a pic of your tank?

 

[xanthurum]

Phosphate barely registers on my test kit which is Red Sea. So it is really low, I feed oyster feast and Rotifeast at least every other day. I also feed my LPS PE mysis and Brine twice a week. Every now and then i mush up half a cube of formula 1 or 2 and disperse it plus Reef Energy two or three times a week.

No pests that I can see signs of on the corals. They just lose large amounts of tissue overnight always from the base up.

A friend suggested macro in the sump could help. Any thoughts?

 

[jackson6745]

The combination of a radion G2 and no fish/low nutrient conditions is not a good one. I had this light and know from experience. More nutrient removal from cheato is not going to help IMO. I would definitely add some fish. Feeding is not the same as fish excrement 24/7.