tweng
Non-member
Hi everyone, I keep a coldwater saltwater tank for a pet lobster I caught while scuba diving. There's also a small crab in the tank. Lately the lobster has stopped eating, or will only take a small amount of food and push the rest away. The crab's appetite is unchanged. I'm trying to figure out why the lobster has stopped eating.
I've been checking the water parameters: ph 8.0 (kh > 15.7), ammonia 0, nitrites 0, nitrate ~40 ppm. The water has a slightly yellow tint which probably indicates dissolved organic compounds from overfeeding / leaving food in the tank for too long. I also had an issue for a while where deep sand had anoxic pockets that smelled bad; I've mostly removed that sand now using a turkey baster to minimize contact with the water column. ph could be higher and so I'm dosing a little Seachem Marine Buffer per day. While nitrate is high, the lobster has had an appetite with high nitrates before. I run a chiller and air stone so temps and oxygen should be stable.
My current hypotheses for why the lobster is eating less:
1. the lobster is about to molt. But I read that lobsters usually stop moving around as much before a molt, and they will often build a barricade out of substrate. My lobster is still active and has not built a barricade.
2. the dissolved organic compounds in the tank are reducing the lobster's appetite. I don't have a cleanup crew so either the filter catches the waste or I have to use the baster to get them out. I noticed maybe a slight improvement in appetite after 10-20% water changes. My filter may not be mature enough to clean the DOCs at the rate I was feeding. I have some activated carbon I can add but I'm not sure if that will help for DOCs.
If anyone has any ideas of why my lobster isn't eating, please chime in. Also, if anyone has thoughts on cleanup crews for coldwater saltwater tanks, let me know -- I was thinking about getting some bristle worms or amphipods, but I'm not sure (I previously had a small batch of amphipods from the beach, but I think there weren't enough to sustain a population).
I've been checking the water parameters: ph 8.0 (kh > 15.7), ammonia 0, nitrites 0, nitrate ~40 ppm. The water has a slightly yellow tint which probably indicates dissolved organic compounds from overfeeding / leaving food in the tank for too long. I also had an issue for a while where deep sand had anoxic pockets that smelled bad; I've mostly removed that sand now using a turkey baster to minimize contact with the water column. ph could be higher and so I'm dosing a little Seachem Marine Buffer per day. While nitrate is high, the lobster has had an appetite with high nitrates before. I run a chiller and air stone so temps and oxygen should be stable.
My current hypotheses for why the lobster is eating less:
1. the lobster is about to molt. But I read that lobsters usually stop moving around as much before a molt, and they will often build a barricade out of substrate. My lobster is still active and has not built a barricade.
2. the dissolved organic compounds in the tank are reducing the lobster's appetite. I don't have a cleanup crew so either the filter catches the waste or I have to use the baster to get them out. I noticed maybe a slight improvement in appetite after 10-20% water changes. My filter may not be mature enough to clean the DOCs at the rate I was feeding. I have some activated carbon I can add but I'm not sure if that will help for DOCs.
If anyone has any ideas of why my lobster isn't eating, please chime in. Also, if anyone has thoughts on cleanup crews for coldwater saltwater tanks, let me know -- I was thinking about getting some bristle worms or amphipods, but I'm not sure (I previously had a small batch of amphipods from the beach, but I think there weren't enough to sustain a population).
