P.H.

[Keg]

I was reading an article on ocean acidification. It said the ocean is becoming more acidified due to rising carbon dioxide levels. This is causing oysters to have trouble forming shells. I started wondering if it might affect crabs. The articles on the web say different crabs are reacting differently.I don't recall any information on what the proper PH should be in the crabitat or what instrument to use.Does anyone have any knowledge of this? I know, I know, I should ask the google, but what would be the fun? Here are sample articles.1) Crabs are bulking up on carbon pollution that pours out of power plants, factories and vehicles and settles in the oceans, turning the tough crustaceans into even more fearsome predators.http://www.japantimes.co.jp/li...ersizing-blue-crabs/2) Effects of Ocean Acidification on Juvenile Red King Crab (Paralithodes camtschaticus) and Tanner Crab (Chionoecetes bairdi) Growth, Condition, Calcification, and Survival http://www.plosone.org/article...journal.pone.00609593) Acidifying oceans may be harmful to porcelain crabshttp://phys.org/news/2013-04-a...porcelain-crabs.html

[dylan644]

Well, naturally most things live well with water that is at a pH of 7. I would assume that the pH should be 7. I've never tested though. I wonder if the salt messes with it... It is corrosive. I guess if your really wanted to fix it you could add something natural like citric acid (orange juice, lemon juice) or vinegar to raise pH or lime to lower it. I wouldn't feel too comfortable doing that myself.

[Keg]

Most of us keep the tank covered that would trap Co2. I assume the Co2 levels that cause acidification are higher in the tank since the crab is excreting Co2 in the process of respiration (or whatever modified gill-breathing is called). I suspect they can live with a high Co2 atmosphere since they extract o2 from evaporating water. But the acidity caused by Co2 is another factor entirely. Also I suppose the acidity gets higher as waste builds up in the tank. PH level might be an indication of when to clean it.I'll try and figure out what is true...

[Keg]

Here are some soil PH testers. I'm going to get one and see what it says.http://www.tequipment.net/Gene...z_57cC ... _pr_sims_t

[JediMasterThrash]

CO2 won't build up in the tank as long as there is some venting (tank shouldn't be completely closed off anyway).CO2 that creates carbonic acid in soil comes from decaying organic matter getting into the water within the soil. It doesn't lower the pH of the soil directly, just the water within it.Pure silica sand is neutral pH, while coir/EE is slightly acidic, 5.8-6.8. This is one of the reasons that a 100% EE substrate is sometimes not recommended. Peat moss and pine are also acidic.If you have greater than 50% silica sand, and keep decaying matter out of the soil as much as possible, you should be able to maintain a good pH.To raise the pH to correct for too high acidicy levels, you would use calcium or magnesium. These wouldn't be added directly, but they are natural ingredients of sea water salts, so occasionally adding some fresh sea water to the substrate may help balance the pH level. Sea water is in the 7.5 to 8.4 rangehttp://en.wikipedia.org/wiki/SeawaterOtherwise as mentioned, limestone or dolomite are good sources of magnesium. Others include rice hulls, vermiculite, hardwood trees.Some good info here:http://www.greenhouse.cornell....HGreenhouseCrops.pdf

[sonny]

thanks for sharing this info. we have had much better success with a cleaner more pure salt mix. we do aerate for at least 24 hours before using to allow the ph to raise to correct levels. i have found that some salt mixes contain less desirable bacteria in there mixes which you can easily see when aerated "instant ocean" is extremely dirty in my opinion causing default in good bacteria ,affecting the ph poorly. we have an ro/di filtration system ,the water is i guess robbed of this capacity during this filtration. it is all very interesting, i believe ph,minerals,and good bacteria plays a bigger role then i can even wrap my brain around ,thanks for the refrences.

[Keg]

This topic seems to have been explored here:http://www.hermitcrabassociati...iewtopic.php?t=79403(I note JMT posted to this thread in 2011)It says, playsand is 7.0, while the natural environment of the crab varies widely depending on which country is measured. 4.7 to 5.1 in one place, as low as 3.7 and as high as 6.85 in others.*******Interesting that is says the hermit crab's exoskeleton is fiberous chitin which does not dissolve the way calcium shells do.Also, it says they seem to be highly adaptable to PH, considering the variablity in native soil they come from.JMT seems to be saying (if I understand) that PH is more critical for aquatic crabs than land dwellers.So is PH a very minor consideration then for land hermit crabs?I think I should still get one of those testers and check.

[finalfantasyxii]

I would like to personally volunteer to head a comprehensive study of soil acidity in comparison to molting and other behaviors of wild land hermit crabs in their native environments. I will be back in a year or so's time to report!P.S. I will be interviewing interested investors to fund the trips to Florida and the Caribbean that this would require.

[Keg]

Don't forget funding for the special vehicle you'll need to withstand the acidity.

[JediMasterThrash]

I don't really know what pH crabs prefer (hopefully finalfantasyxii will tell us in a year!)But it seems that the beach will be slightly basic, and forest floor will be slightly acidic. And some crabs spend more time in one location versus another.If crabs are fairly adaptable, then perhaps it's not too big of an issue?

[Keg]

I agree JMT. I'm kinda thinking that crabs can find a huge gradient of PH, temperature, heat and who knows what else in nature to choose from. Moving to a comfortable spot might be a significant part of their ability to adapt.I suspect the larger tanks might help in that respect.May I offer an example? The air in Arizona is dry... I would think that the crab would prefer to stay down by the wet sand... But she invariably climbs up on branches when the top is off the crabitat. I'm thinking that she can compensate for the dryness by filling her shell with water, but she cannot compensate for the excessive heat here. So for the most comfortable compromise, she climbs up where she can feel the effects of the air conditioner.As far as PH, there is no doubt a gradient, but for all I know, land crabs are oblivious to it (unlike aquatic crabs who have diverse and measurable effects).