HCA: Hermit Crab Association

What is the recommended longest time frame to go between fully replacing substrate?

You only have to do a sub change if there is an emergency, like a bacterial bloom or flood. It's been over 2 years and I just add sand when needed. Curly says she's never changed her sub and I think she's had her crabs over 10 years.

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LOL, yeah, I'm over 11 years now! LOL! I have of course added more sub, as my crabs have grown and as I have upgraded to larger crabs. Some of the other admins/mods do change out their sub every year or two. LOL.

curlysister wrote:LOL, yeah, I'm over 11 years now! LOL! I have of course added more sub, as my crabs have grown and as I have upgraded to larger crabs. Some of the other admins/mods do change out their sub every year or two. LOL.

I'm going with your method and just adding sand as needed. I use to change it out every 3 months before I found the HCA. I feel so horrible looking back, because I would dig up crabs to do it. I didn't know how bad that was. The HCA really changed my crabs' life for the better.

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I change my substrate every couple of years, but I don't dig up crabs specifically to do so. Either I catch them when they are up, or during something else where there's no choice like in an emergency or if a tank needs to be moved.

CrabbyLover77 wrote: ↑

Sat Jul 16, 2022 7:44 pm

You only have to do a sub change if there is an emergency, like a bacterial bloom or flood. It's been over 2 years and I just add sand when needed. Curly says she's never changed her sub and I think she's had her crabs over 10 years.

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Okay, thank you. My substrate did get a bit wet, but unsure if it flooded or if there was a bacterial bloom. I tested the rightside sticking something down all the way and no standing water at that time. I'll upload some pics below. One of my two crabs just went down this week after spending a week sitting in the food dish... so thinking they are molting! But I was planning on digging down and seeing if the substrate smells at all. Since that seems like a surefire way to know if it should be replaced or not? Of course, it would be done only when both are above ground.

I guess if it doesn't smell I may leave it. It's probably been close to 10 years set up without any substrate changes, that I can remember.

It's great to know Curly has also had no changes for around the same timeframe and crabs are doing well, that helps me feel better!

Im team change every couple of years, I usually change out a small portion every year. Waste builds up, and without some removal of it, it could eventually cause quite a build-up nitrogenous based compounds, which may effect the chemistry of the substrate - like increased acidicity due to build-up of acids.

aussieJJDude wrote: ↑

Mon Jul 18, 2022 7:06 am

Im team change every couple of years, I usually change out a small portion every year. Waste builds up, and without some removal of it, it could eventually cause quite a build-up nitrogenous based compounds, which may effect the chemistry of the substrate - like increased acidicity due to build-up of acids.

The other thing is that I only have two crabs. I think you have a lot more than that, right?

I'm a long time crab keeper and I've never changed out my sub completely. I still have my original sub from when I got my first crab in 2008-ish. My first tank was a 10 gallon. Later that same year I rescued a bunch of crabs--100's--and filled many, many tanks with crabs. I rehomed all but about six of those. The sub is a combo of my original sub from 2008, and newer sub from upgrading my tank. I'm down to a single 75 gallon tank with 3 jumbos, 2 XL's and one large. They've been together for years in the same sub.

Thanks for all the reassurance everyone!