Moon Jellyfish

[mpowell]

Hello! Does anyone have any knowledge about how to fix low Alkalinity in a Moon Jelly system? My Alkalinity is running at 105ppm which is INCREDIBLY too low resulting in my pH acting wonky and dropping. I know a possible solution is to add bicarb but what I don't know is if that would harm my jellies. Do I add a little at a time or are there other options? Also, my source water for water changes is running at a ideal pH and ALK.

 

[Jay Hemdal Verified Community Expert]

Hello! Does anyone have any knowledge about how to fix low Alkalinity in a Moon Jelly system? My Alkalinity is running at 105ppm which is INCREDIBLY too low resulting in my pH acting wonky and dropping. I know a possible solution is to add bicarb but what I don't know is if that would harm my jellies. Do I add a little at a time or are there other options? Also, my source water for water changes is running at an ideal pH and ALK.

Welcome to Reef2Reef!

I’ve kept moon jellies since 1993, but I’m not an expert on alkalinity.

I’ve found though, that since you need to avoid air bubbles with jellies, these tanks often have poor gas exchange, which increases the CO2, which in turn uses up alkalinity. I get around that by using sumps in my jelly tanks, and I can aerate the water very heavily there.

One test you can try - take some water out of the tank, measure the pH, then aerate it heavily for 12 hours. If the pH rises substantially, then high CO2 is the issue.

Jay