Zoas dying off.

[danlechem]

I've had a water box tank running for a couple of months. A few weeks after setting up I got a mixed bunch of soft and LPS corals from a breakdown. Since then I've lost several including large torch and zoas now following suits along with a goni and second torch

My levels have remained fairly stable since introducing the corals.

KH 7 .5
Iammonia 0.15
nitrate between five and 10
P4 around 0.05
PH 8.1.
Temp 24.5
Sg 35


I do daily water changes around 4%.

I have adjusted wave makers to reduce flow around the bottom of the tank and I feel this is at a minimum. I have two near the top of weir and one small one near to the bottom facing behind my rock to keep things moving.

Lighting is one GR 15 set up 45% for six hours however during the first few weeks I was running this for nine hours at 60% which I think caused some of the initial problems with other corals dying off.

Do you think the corals are still recovering from too much light or could there be other issues that I'm not picking up on? I've attached a ohoto or two to show position of wave makers , apologies for the clarity I've added coral snow. Thanks. Dan

 

[Dom]

Zoas do well with minimum light and flow. And your Zoas don't seem like they are dying off as much as they seem to have closed.

Perhaps some livestock is walking across them while scavenging?

You haven't mentioned the capacity of your tank. Also, daily water changes may be doing more harm than good.

Water changes can be disruptive to the tank. Doing them daily doesn't give the tank time to bounce back.

I would suggest that you stick to weekly 20% water changes and monitor for a few weeks.

 

[danlechem]

Display Capacity is around 180 litres. I only have some really small hermits cuc. I had a rogue shrimp but managed to catch him a week or so ago.

Water changes are done automatically- I'll reduce the frequency.

I've reduced the flow and rolled back the light intensity and see how they go over the next week. Cheers.

 

[bossman818]

Ammonia should be zero.

 

[Mr. Mojo Rising]

How fast or slow do the corals die?

The parameters look fine - alk is a bit low but should be ok'ish - when parameters are fine it comes down to lights and flow IMO. Your size tank with only one light fixture at 45% for 6 hours seems low to me. Not talking about only the zoa's, you mention you have lost 'several' corals, but there is nothing in the parameters that will cause so many losses. Lights or flow (too much or too little) can cause heavy coral losses. High light or flow kills corals very fast, within a day or two, low light or flow will kill very slow, it takes weeks or months. Torch corals can take high lighting, so I doubt the lighting was too high.

Just my 2 cents, but you might want to consider to rent a par meter to know for sure.

 

[danlechem]

How fast or slow do the corals die?

The parameters look fine - alk is a bit low but should be ok'ish - when parameters are fine it comes down to lights and flow IMO. Your size tank with only one light fixture at 45% for 6 hours seems low to me. Not talking about only the zoa's, you mention you have lost 'several' corals, but there is nothing in the parameters that will cause so many losses. Lights or flow (too much or too little) can cause heavy coral losses. High light or flow kills corals very fast, within a day or two, low light or flow will kill very slow, it takes weeks or months. Torch corals can take high lighting, so I doubt the lighting was too high.

Just my 2 cents, but you might want to consider to rent a par meter to know for sure.

Yeah I had it set at higher intensity for a longer period but watched. Video online of a similar sized tank and I've copied his settings. I'll try and get my hands on a par meter. I initially set it high because the tanks 24" deep with and 8" bracket and I've read the xr15s aren't great other than spread.

The way the torch died off i was leaning toward high light and flow. I'm dialling them right back but I also noticed algae growing on the closed zoas which I presumed meant tge flow was too low. Don't know what to do for the best!