Normal
Salinity isn't a huge topic at all. I've never even seen it mentioned before. It's a non-topic as far as I know. You haven't hit upon some sort of taboo or controversy. I think the issue here is that you are a novice keeper who still clearly needs to learn the basics and you are now a bit too ambitious in your experimentation with no foundation. The first step of any experiment is purposeful background research, followed by a thoughtful and solid experimental design. I'm not even sure what you're trying to determine or how what you are doing will support whatever hypothesis you have in mind.My primary critique of your "experiment" is that there are many uncontrolled variables here that you need to control for including the salinity of the soil, the age and type of tarantula and the sample size. Without controlling for these, you will learn exactly nothing from this sort of experiment.Furthermore, you say you are trying to find out if it is a "requirement." Based on the fact that literally no one I know of has added salt to their substrate deliberately, I think we can safely say that adding saline is definitely not a requirement to keeping tarantulas healthy.What do you even mean by "salinity in the air is good" in their native environment? Climate? Erosion? What???Spiderlings of all species need some moisture in their substrate, but it does not have to be salty. I've had hundreds of spiderlings over the years and never kept them salty. That sample size is far more significant than your single sling. Also, not only is it not necessary to sterilize your substrate initially, it is actually harmful to remove and clean it periodically. You are disturbing your spiders every time you do this. In the wild, these animals will construct a single burrow and live in it until they die (if they're female) or mature and wander off in search of a mate (if male.) Keep your spiderlings in deep, damp substrate and allow it to burrow undisturbed. Rehouse it as needed, but less often is best. There is still some speculation about why adult Grammostola rosea are less likely to burrow than many species, but having to construct a burrow as an adult is unnatural for them. I have a large female and she does dig. A spiderling digging is normal, not some big accomplishment to be credited to salt.I applaud curiosity and experimentation, but only after you have learned the basics of husbandry. I can't figure out if you think you already know enough or if you realize that you're a beginner because your post was a bit conflicting, but my advice is that you learn more about the two species you already have and then learn the basics of other species before you try to conduct groundbreaking research on tarantula physiology with such a poorly designed experiment.Here's some background on fish and how that aquarium salt works for them. The salt you are using is a mineral salt for freshwater fish, not for marine fish. The minerals in the water are necessary electrolytes for fish respiration. Their gills don't function properly in distilled water, and many popular fish species come from water with a high dissolved mineral content which this mineral salt mimics. It is useful as a disease preventative because higher-than-ideal salinity slightly irritates the fish, causing them to produce a thicker mucus covering on their bodies. This mucus is part of their immune system and makes it more difficult for parasitic organisms to penetrate their skin. It also changes the osmotic balance, so if a fish has dropsy, which is a swollen body due to water retention, increasing the salinity of the water helps to draw that extra fluid from their bodies.Do you see how none of this is applicable to tarantulas? The only time I have ever heard of someone deliberately exposing a tarantula to salt was when the spider had a severe case of nematodes coupled with a bacterial infection. The spider's comparatively larger size enabled it to withstand the salinity longer than the parasites could. Incidentally, you realize that mites are a very close relative of tarantulas, right? If something kills them, it isn't good for spiders, either. The difference would be the dose relative to their size.Apologies for the length of this post and for any weirdness caused by my iPad's autocorrect and predictive typing. We hates it, precious.
Salinity isn't a huge topic at all. I've never even seen it mentioned before. It's a non-topic as far as I know. You haven't hit upon some sort of taboo or controversy. I think the issue here is that you are a novice keeper who still clearly needs to learn the basics and you are now a bit too ambitious in your experimentation with no foundation. The first step of any experiment is purposeful background research, followed by a thoughtful and solid experimental design. I'm not even sure what you're trying to determine or how what you are doing will support whatever hypothesis you have in mind.
My primary critique of your "experiment" is that there are many uncontrolled variables here that you need to control for including the salinity of the soil, the age and type of tarantula and the sample size. Without controlling for these, you will learn exactly nothing from this sort of experiment.
Furthermore, you say you are trying to find out if it is a "requirement." Based on the fact that literally no one I know of has added salt to their substrate deliberately, I think we can safely say that adding saline is definitely not a requirement to keeping tarantulas healthy.
What do you even mean by "salinity in the air is good" in their native environment? Climate? Erosion? What???
Spiderlings of all species need some moisture in their substrate, but it does not have to be salty. I've had hundreds of spiderlings over the years and never kept them salty. That sample size is far more significant than your single sling. Also, not only is it not necessary to sterilize your substrate initially, it is actually harmful to remove and clean it periodically. You are disturbing your spiders every time you do this. In the wild, these animals will construct a single burrow and live in it until they die (if they're female) or mature and wander off in search of a mate (if male.) Keep your spiderlings in deep, damp substrate and allow it to burrow undisturbed. Rehouse it as needed, but less often is best. There is still some speculation about why adult Grammostola rosea are less likely to burrow than many species, but having to construct a burrow as an adult is unnatural for them. I have a large female and she does dig. A spiderling digging is normal, not some big accomplishment to be credited to salt.
I applaud curiosity and experimentation, but only after you have learned the basics of husbandry. I can't figure out if you think you already know enough or if you realize that you're a beginner because your post was a bit conflicting, but my advice is that you learn more about the two species you already have and then learn the basics of other species before you try to conduct groundbreaking research on tarantula physiology with such a poorly designed experiment.
Here's some background on fish and how that aquarium salt works for them. The salt you are using is a mineral salt for freshwater fish, not for marine fish. The minerals in the water are necessary electrolytes for fish respiration. Their gills don't function properly in distilled water, and many popular fish species come from water with a high dissolved mineral content which this mineral salt mimics. It is useful as a disease preventative because higher-than-ideal salinity slightly irritates the fish, causing them to produce a thicker mucus covering on their bodies. This mucus is part of their immune system and makes it more difficult for parasitic organisms to penetrate their skin. It also changes the osmotic balance, so if a fish has dropsy, which is a swollen body due to water retention, increasing the salinity of the water helps to draw that extra fluid from their bodies.
Do you see how none of this is applicable to tarantulas? The only time I have ever heard of someone deliberately exposing a tarantula to salt was when the spider had a severe case of nematodes coupled with a bacterial infection. The spider's comparatively larger size enabled it to withstand the salinity longer than the parasites could. Incidentally, you realize that mites are a very close relative of tarantulas, right? If something kills them, it isn't good for spiders, either. The difference would be the dose relative to their size.
Apologies for the length of this post and for any weirdness caused by my iPad's autocorrect and predictive typing. We hates it, precious.