Pithos crab questions

[SallyWho]

I was on here searching for advice on getting rid of bubble algae and trying to decide if getting a few emerald crabs would be worth it, when I saw a post about pithos crabs! I'd never heard of them, but after a little reading on them, they sound great! But I couldn't find any guidance on how many one should buy. I have a 90g with a significant infestation- not every rock is coated but those that are, ARE. Do they tend to stay on/near the bottom of the tank, or will they climb onto rock structures higher up? And once all the bubble algae is gone, what should I feed them? Any advice would be appreciated, thanks!

 

[TX_REEF]

I was on here searching for advice on getting rid of bubble algae and trying to decide if getting a few emerald crabs would be worth it, when I saw a post about pithos crabs! I'd never heard of them, but after a little reading on them, they sound great! But I couldn't find any guidance on how many one should buy. I have a 90g with a significant infestation- not every rock is coated but those that are, ARE. Do they tend to stay on/near the bottom of the tank, or will they climb onto rock structures higher up? And once all the bubble algae is gone, what should I feed them? Any advice would be appreciated, thanks!

I love my pithos crabs! However, if your bubble algae problem is extensive, they won't fix it. I do see mine pop some bubbles on occasion and pick at them. I have 3 in a 72 gallon. Emerald crabs are the same way, not voracious predators of bubble algae but will pick at them if they come across them. However, I have seen my emerald crabs eat healthy LPS coral, so they live in the sump of my frag tank now. My pithos crabs have never eaten coral to my knowledge, I've even seen them gently remove hair algae from some of my coral skeletons.

Pithos crabs seem to be mostly nocturnal in my experience. They tend to bury themselves in the sand during the day and explore the tank and rockwork by night. For a 90 gallon, 5 or so would be good. As far as source, I cannot recommend @reefcleaners enough. Their customer service and products are second to none for cleanup crews. Here's their site: https://www.reefcleaners.org/aquarium-store/tank-cleaners/pitho-crab-detail

 

[SallyWho]

I love my pithos crabs! However, if your bubble algae problem is extensive, they won't fix it. I do see mine pop some bubbles on occasion and pick at them. I have 3 in a 72 gallon. Emerald crabs are the same way, not voracious predators of bubble algae but will pick at them if they come across them. However, I have seen my emerald crabs eat healthy LPS coral, so they live in the sump of my frag tank now. My pithos crabs have never eaten coral to my knowledge, I've even seen them gently remove hair algae from some of my coral skeletons.

Pithos crabs seem to be mostly nocturnal in my experience. They tend to bury themselves in the sand during the day and explore the tank and rockwork by night. For a 90 gallon, 5 or so would be good. As far as source, I cannot recommend @reefcleaners enough. Their customer service and products are second to none for cleanup crews. Here's their site: https://www.reefcleaners.org/aquarium-store/tank-cleaners/pitho-crab-detail

Thanks! I do try to remove as much manually as I can, but it really gets away from you. I do have a foxface, but it doesn't care a whit about it! :D I usually call him Spike Lee (for the spines), but I've taken to calling him Useless lately!

Do your pithos crabs ever show interest in higher rocks, or have you only noticed progress down lower in the tank? I'm wondering what to do about the upper parts of my scape.

 

[TX_REEF]

Thanks! I do try to remove as much manually as I can, but it really gets away from you. I do have a foxface, but it doesn't care a whit about it! :D I usually call him Spike Lee (for the spines), but I've taken to calling him Useless lately!

Do your pithos crabs ever show interest in higher rocks, or have you only noticed progress down lower in the tank? I'm wondering what to do about the upper parts of my scape.

in my experience, they tend to stay lower down on the rockwork and in the sand. You could manually place them higher on the rocks, I think they can't see too well so it would be easy to pick them up and relocate. I even hand feed mine occasionally just because I find it amusing.

One more comment on bubble algae, and this is controversial based on who you ask, but I found success using Algaefix to cull my bubble algae population. I haven't noticed any negative side effects when following the instructions. Some folks use a product called "Vibrant", but Randy here on the forum has mentioned that the active ingredient is the same as that in algaefix, so might as well just use the honest algaecide.

API Algaefix: https://amzn.to/45SCnQy

 

[paragrouper]

I use emeralds, although I read a number of accounts where folks say the pathos work better. I have three in my 32 gallon tank. They did not do the job alone, as I manually removed as much as I could easily get to. After a time I noticed a lot of bubble getting pulled up to my AIO inlets and the back of the power heads, as the crabs would dislodge clusters of bubbles to get at the yummy goodness underneath. Now I don’t find bubble algae.

 

[DaJMasta]

I've got a few of both, and behavior wise, same conclusions: they hide in the sand during the day and come out at night and won't specifically eradicate bubble algae but can help management. They're larger than emeralds and they are more likely to be closer to the bottom of the tank, but I have certainly seen mine climb up on the rocks particularly near the glass.

You maybe be able to get a few and then manually remove chunks of the bubble algae - it tends to come off in a mat. If you were going to go the chemical route, I'd personally recommend a 2-3x dose of fluconazole over an algaecide , but there are probably options here.

 

[BrokenReefer]

I have (had 10) somewhere around 5 in my 150g system. They bury themselves in the sand, come out at night; not sure if they scavenge the rock work as much as the sand. I also got a tuxedo urchin which has been mowing down the bubble algae in my tank. It's been quite impressive to see the bubble algae nearly evaporate - now it's taken several weeks but I'm fine with that. I may add one more urchin but that's a TBD.

I would say get a tuxedo urchin and Pithos with Emeralds.

 

[SallyWho]

I have (had 10) somewhere around 5 in my 150g system. They bury themselves in the sand, come out at night; not sure if they scavenge the rock work as much as the sand. I also got a tuxedo urchin which has been mowing down the bubble algae in my tank. It's been quite impressive to see the bubble algae nearly evaporate - now it's taken several weeks but I'm fine with that. I may add one more urchin but that's a TBD.

I would say get a tuxedo urchin and Pithos with Emeralds.

Huh. I've never actually considered getting an urchin. I'll have to read up on that to see if that would be a good fit for my tank.

 

[mfinn]

I added 3 pitho crabs to my 66 gallon tank. One died within a couple days, but the other 2 are still there.
I didn't have alot of bubble algae, but it was there. The emeralds got the bubble algae down but never finished it off.
After a couple months I can not see any bubble algae on the rocks at all.
I do see a couple on my urchins. 2 of them are carrying a couple around each.
A couple bubbles on my powerheads, but basically the tank is clean.

 

[coco3suns]

Huh. I've never actually considered getting an urchin. I'll have to read up on that to see if that would be a good fit for my tank.

So I have a pencil urchin, had algae all over him lol. I bought phito crabs and 2 of them were tearing apart my poor urchin . It was all at like 2:30a.m. I reached in the tank and grabbed the mess of claws. Untangled them, which took about 30 minutes!!! I put my poor urchin in my clown and seahorses tank to mend. It's been about 2 weeks now and he's doing great . He always minded his own business. The crabs now live in a smaller tank. 1 or 2 of them were killing machines .

 

[Huskereef]

I have (had 10) somewhere around 5 in my 150g system. They bury themselves in the sand, come out at night; not sure if they scavenge the rock work as much as the sand. I also got a tuxedo urchin which has been mowing down the bubble algae in my tank. It's been quite impressive to see the bubble algae nearly evaporate - now it's taken several weeks but I'm fine with that. I may add one more urchin but that's a TBD.

I would say get a tuxedo urchin and Pithos with Emeralds.

Did you buy your tuxedo from a LFS or online? Thinking about buying one hoping it will go after bubble algae, pithos are very slow workers

 

[Lonster00]

Realize this is an old post, but have had similiar problems in the past. Ive used small( hard to find small ones under an inch) pink urchins in the past . When I see an order come in to LFS I get them and put maybe 6 in one of my reef tanks. They really do an amazing job cleaning the liverock. Ive had bigger ones actually remove the coraline algea from the rockwork. I have to leave every summer for several months and have a fish girl taking care of my weekly tank maintenance. I always stock small ones in each tank. Never big ones though , and they can get 3-4 inches across. They are able to pick up corals and crab shells, etc, and carry them around the tank. The little ones only pick up small shells that are empty. Be aware though, I had one that somehow ate through a powerhead cord and did electrocute the tank that had a clown pair. Ive since put black cord covers on all heater , powerhead, and basically any power supply thats in the tank to prevent it happening again. Never had that happen in 20 years in the hobby but trust me, it does.

 

[coco3suns]

Realize this is an old post, but have had similiar problems in the past. Ive used small( hard to find small ones under an inch) pink urchins in the past . When I see an order come in to LFS I get them and put maybe 6 in one of my reef tanks. They really do an amazing job cleaning the liverock. Ive had bigger ones actually remove the coraline algea from the rockwork. I have to leave every summer for several months and have a fish girl taking care of my weekly tank maintenance. I always stock small ones in each tank. Never big ones though , and they can get 3-4 inches across. They are able to pick up corals and crab shells, etc, and carry them around the tank. The little ones only pick up small shells that are empty. Be aware though, I had one that somehow ate through a powerhead cord and did electrocute the tank that had a clown pair. Ive since put black cord covers on all heater , powerhead, and basically any power supply thats in the tank to prevent it happening again. Never had that happen in 20 years in the hobby but trust me, it does.

Oh gosh. The urchin did that? I have a clown pair and about a year or so ago my female clown chewed through my heater cord. It was winter and when I noticed how cold the water was I kinda freaked out. I unplugged heater waited a few minutes than plugged back up. The display lit up always so I thought it worked. Waited a bit and reached into water, still very cold. I had to catch those little buggers and accumulated them into my 75 gallon till it heated up. Well like a hr later, still cold so I took heater out and gave it a good cleaning
That's when I noticed the cord. Im so thankful I didn't get electrocuted!!!! Than about 6-8 months later she chewed through my uv light cord! I was so darn mad. I had to order another bulb.