Lost first fish and a cleaner shrimp. Looking for the reason.

[Stonker]

Hi. Let me first off start by saying yes, my tank is cycled :p I’m using all cured live rock and I used a Fluval cycle product, this plus water and sand from an existing aquarium. Ammonia is zero, nitrites are zero and there’s a hint of nitrate.
The tank is about 8 weeks old. It’s had the uglies for a couple of weeks so I thought I’d add some CUC, and a hardy fish. I added 2 hermits, a couple of trochus snails, a cleaner shrimp and a Royal Gramma. The shrimp was dead within hours, the Gramma 3 days later. The snails and crabs are fine.
Prior to this I was given a couple of frags of Zoa, a tree coral and a small mushroom. To make these happy I directed the flow from my outlet down towards them, but in doing so I reduced surface agitation quite a bit.
Suddenly I’m seeing a large drop in PH (7.2-7.4 at times). I’m assuming now it’s because of a CO2 build up. I’ve since increased agitation. I have a small skimmer running which provides some O2.
My question is, is that drop in PH enough to kill a fish and a Cleaner Shrimp?
What else do I need to be checking for?
All input is appreciated.

 

[JetBoggs]

Hi there,
Your pH drop likely didn’t directly kill the Royal Gramma and Cleaner Shrimp, but the sudden swing from reduced surface agitation and CO₂ buildup probably caused severe stress and low oxygen, which shrimp are especially sensitive to. The shrimp’s death may have triggered a small ammonia spike that finished off the already stressed fish. Check alkalinity as it should be around 8–10 dKH and ph around 8.1-8.3, saliny and temperature stability, as low alkalinity or sudden changes can make pH swings worse. Keep strong surface agitation and good skimmer airflow, and wait a few weeks before adding new livestock once pH stabilizes around 8.0–8.3. But definitely try to increase surface agitation as this seems to be the core issue!

 

[JetBoggs]

Just improve gas exchange :)

 

[Gumbies R Us]

What are your other parameters and what are you using to test them?
How does filtration look in your tank?
How are you acclimating your livestock?
Temperature of your tank?
Where are you getting the livestock from?

 

[Mr. Mojo Rising]

Did you test the water for ammonia after the fish death?
How did you cycle the tank and for how long? I like to see somewhere at around 20 to consider it cycled.
Did you measure the LFS salinity and acclimate accordingly? LFS water usually keeps much lower salinity than we do.

 

[Fish Fan]

Hi. Let me first off start by saying yes, my tank is cycled :p I’m using all cured live rock and I used a Fluval cycle product, this plus water and sand from an existing aquarium. Ammonia is zero, nitrites are zero and there’s a hint of nitrate.
The tank is about 8 weeks old. It’s had the uglies for a couple of weeks so I thought I’d add some CUC, and a hardy fish. I added 2 hermits, a couple of trochus snails, a cleaner shrimp and a Royal Gramma. The shrimp was dead within hours, the Gramma 3 days later. The snails and crabs are fine.
Prior to this I was given a couple of frags of Zoa, a tree coral and a small mushroom. To make these happy I directed the flow from my outlet down towards them, but in doing so I reduced surface agitation quite a bit.
Suddenly I’m seeing a large drop in PH (7.2-7.4 at times). I’m assuming now it’s because of a CO2 build up. I’ve since increased agitation. I have a small skimmer running which provides some O2.
My question is, is that drop in PH enough to kill a fish and a Cleaner Shrimp?
What else do I need to be checking for?
All input is appreciated.

I'm sorry about your losses and issues here.

My first thought is that your pH didn't drop nearly as low as 7.2, that's not really possible in a tank with aragonite rocks and sand (which buffer the pH to about 7.6) and a typical, good quality salt mix. You pH may be low, but it's not as low as you think, and not likely the cause of what's going on. I'd bet it's no lower than 7.8, and a lot of people run their tanks at 7.8-ish without concern. What are you using to test pH? If it's a pen style probe, was it calibrated correctly?

You do want to keep your return nozzle aimed up at the surface to increase gas exchange. For that reason, you may need to add a small circulation or wave maker pump to increase flow in your tank. This will help with your uglies, and your corals will appreciate the flow too. Your skimmer will also increase gas exchange, so that's good that you're running one.

I think this points to acclimation issues and/or disease.

I hope that helps!

 

[Stonker]

Thanks for the responses. I've just returned from the LFS who advised that my pH and salinity are slightly low, but nothing that should have caused deaths, as the PH fluctuates throughout the day anyway. Apparently my salinity is around 1.022. I need to check my refractometer. I've got some water warming up around 1.026 so I'll add a little of that.
General conscensus is that it was probably an O2/CO2 issue from lack of agitation, causing stress.
I've picked up a wavemaker today.
I'll be monitoring things for a few weeks now.

 

[Stonker]

I'm sorry about your losses and issues here.

My first thought is that your pH didn't drop nearly as low as 7.2, that's not really possible in a tank with aragonite rocks and sand (which buffer the pH to about 7.6) and a typical, good quality salt mix. You pH may be low, but it's not as low as you think, and not likely the cause of what's going on. I'd bet it's no lower than 7.8, and a lot of people run their tanks at 7.8-ish without concern. What are you using to test pH? If it's a pen style probe, was it calibrated correctly?

You do want to keep your return nozzle aimed up at the surface to increase gas exchange. For that reason, you may need to add a small circulation or wave maker pump to increase flow in your tank. This will help with your uglies, and your corals will appreciate the flow too. Your skimmer will also increase gas exchange, so that's good that you're running one.

I think this points to acclimation issues and/or disease.

I hope that helps!

That's good to know about he PH, could be my test kit

 

[Fish Fan]

That's good to know about he PH, could be my test kit

Yes, remember we largely use home, hobby-level kits, not laboratory grade testing

 

[JoJosReef]

Thanks for the responses. I've just returned from the LFS who advised that my pH and salinity are slightly low, but nothing that should have caused deaths, as the PH fluctuates throughout the day anyway. Apparently my salinity is around 1.022. I need to check my refractometer. I've got some water warming up around 1.026 so I'll add a little of that.
General conscensus is that it was probably an O2/CO2 issue from lack of agitation, causing stress.
I've picked up a wavemaker today.
I'll be monitoring things for a few weeks now.

How about acclimation? What was the salinity of the bag water of the fish and shrimp? Did you drip acclimate or acclimate by adding a fraction of water multiple times over an hour?