high salinity causes what probs???

well, seems as if my refractometer needed calibration. did about 4 different tests, floating vs 2 different refracto's, recalibrated with 2 diff calibration fluids, tested NSW, and mixed up a perfect sample of 38.2 g salt/ltr of 0tds water to get 1.026 [red sea coral pro], calibrated the refracto again. my tank sg is at 1.030, and has been there for at least a long while, verified. what are the consequences of high salinity as i lower it over a couple weeks?

1.030 is not too bad IMO, as long as you adjust it down over several weeks. I believe the slow change of salinity is not too bad for our critters as long as it's a slow change, and stays within .010 of NSW.

I check my refractometer every use with RO, and about once a month with cal solution. It's never that far off, but I think that's because I check it so often.

I doubt you would see any adverse health effects if they haven't turned up already. In my opinion, low salinity tends to do much more damage than high salinity. Fish might be a little more prone to parasites and adjusting for the hypersaline solution might be more energetically costly to their metabolisms, but you won't see the invertebrate tissue damage like you would with low salinity.

Believe it or not, high salinity dehydrates your fish. The salt in your tank pulls moisture out of your fish via osmosis. Fresh water fish literally "drink" water like we do but saltwater fish, their water is absorbed through their skin.

As mentioned a sg of 1.030 shouldn't cause any effects since that not to terribly high.
Bringing it down slow is safe but not necessary. The fishes body can more easily regulate dropping salinity. However bringing it UP need to be done extremely slow.

Fwiw, the calibrating solution evaporates water causing the solution to get more salty. Ime, you should purchase a new bottle about every 3 months or so...

Its actually the other way around Tizzo. Fresh water fish rarely drink, and urinate diluted urine constantly, to expell excess water that they take in from their skin. Their environment is trying to dilute them. Salt water fish drink large amounts of water and urinate super concentrated urine, less often. Their surrounding environment is trying to "dry them out".

It is theorized that because saltwater fish drink more, they are more sensitive to water pollution, as their kidneys must work harder than a freshwater fishes.

Did I have it backards?? Hmmm. Ok Variko- it's on!

Water Chemistry for the Marine Aquarium by John H. Tullock is where I got it from.

i feel better now. could 1.030 help grow algae, weird algae that nobody has, bright lime green with no hold at all, red, and a dull gray w/brown tip flimsy algae only on rocks. different algae in both tanks b/c of the lighting. what is the well-done marine algae book???

Just to clarify, Tizzo is right in that FISH do better with salinity drops, However INVERTS do worse with salinity drops.

Fish can compensate pretty easily, but inverts do not have the same salt balancing equipment and a drop in salinity causes rapid swelling of soft tissue which can lead to permanent damage/death. This is why freshwater dips are so effective at killing parasites, the fish is fine, but the parasite suffers severe tissue damage.

Originally Posted by Variko

Water Chemistry for the Marine Aquarium by John H. Tullock is where I got it from.

crap, your right...

@ spiny. Inverts have the same body chemistry as the sea water around them right? which is why they are so affected by salinity. They depend on the salinity of the outside water, to keep their chemistry correct. A fish can regulate its own body chemistry, and can adapt to different salinities becasue of that internal regulation.

Yep that is exactly right. The official term is osmoconformation, meaning they conform to the osmolarity of their surroundings. There are some inverts that do have mechanisms to deal with changes in salinity, but this is the exception rather than the rule. Halocardina rubra shrimp can go from Seawater to freshwater in one swoop and appear to be unaffected, even fish can't do that. But 99.9% of inverts have trouble dealing with saltwater that is anything other than what they naturally live in.

Could this maybe the reason for the clam not making it ?

Clams have the advantage of being able to close up and keep bad environmental conditions out, they also have a cool metabolic adaptation to go without oxygen for quite a while. So short term changes in salinity will probably just make the clam close up and wait it out, but long term salinity imbalance will cause problems. But they can live within a small range of salinity as is demonstrated by clams living in the super salty Red Sea and clams living in the less salty Pacific. As long as changes are slow and kept within a reasonable range (1.024-1.028) most things will do fine.

Originally Posted by houndsbayman

Could this maybe the reason for the clam not making it ?

funny, i was wondering if the clams would get upset if he lowered the salinity too much. I've never had my salinity swing with clams in my tank, so i don't know how they'd react, but i remember it being said that the tahitian maximas were collected in high salinity lagoons.

Paul.... how are the clams.. and what made you double...triple check the Sg... did something not look right?

a buddy on drc checked things [he's a testing freak] and things did not agree betweeen 2 refracto's and a good floating hydro and both calibration fluids. we mixed up a specific portion of salt and a liter of water to get exactly 1.026, as is on the tub of salt. my sg has not 'fluctuated' it's been stable, steady, and inaccurate for a while. so we're bringing it slowly down, baseed on the new standard of reliability--calibrated refracto and the floating.

Originally Posted by houndsbayman

Could this maybe the reason for the clam not making it ?

Not to dig up a dead horse or anything but if you go back and read that thread John part of the argument from that vendor was that people were keeping their salinity lower then where those clams came from so if you follow the advice from that vendor the salinity that Paul is reporting now is right about where that vendor suggests keeping it.

How often do refractometers need calibration? Should I own 2 in case 1 has a problem? Do they last indefinately or does the salt water harm them over time? How are your other clams doing btw Shmoliken?

I calibrate mine every few months. If its a good quality unit and its not dropped or damaged in any way it shouldnt need to be calibrated that often.