why salinity, 1.024 vs. 1.018

[timdam]

why do they say to keep your salinity for reefs at 1.024.... and then for fish only tanks it should be at like 1.018?

i mean, will it hurt anything to keep "fish only" tanks at 1.024 also?

[Fizz71]

The lower salinity helps kill off bacteria and other parasites that could harm our fish because the parasites can't survive in a hypo salinity environment, but the fish can...quite happily. Unfortunately the low salinity it also kills off our corals. I run between 1.025 and 1.026 personally.

But the answer to your question is NO...1.024 is fine for a fish only system, some just consider it a waste of salt.

[timdam]

well, if keeping it low will help kill off any possible parasites, then i guess i will keep my fish only system at a low salinity.

[Toddrtrex]

well, if keeping it low will help kill off any possible parasites, then i guess i will keep my fish only system at a low salinity.

1.018 isn't going to effect parasites, needs to be even lower -- 1.009 -- which isn't good for the fish long term.

IMO, I don't see any real reason not to keep it at 1.026. Should only go down to 1.009 if you have your fish in a QT.

[jason2459]

Only reason I can see keeping it 1.020-1.024 range would be in a Fish only tank and you want to save on salt. Would not help at all with parasite control. I wouldn't go below 1.020. You're other inverts like snails, crabs, and shrimp, if any, would not be to happy.

[timdam]

i don't see where u can really save too much in salt anyways. it's not like when u need to top off, u are losing salt. only on water changes. i guess i will raise my salinity now in my fish only tank!

[jason2459]

i don't see where u can really save too much in salt anyways. it's not like when u need to top off, u are losing salt. only on water changes. i guess i will raise my salinity now in my fish only tank!

Depends on the size of the tank, how often, and the amount that is changed. Could be a significant amount of salt. That being said, I used to always kept mine at 1.025 and with my new tank at 1.0264.

[returnofsid]

Lower salinity will do a couple of things.

1. Negatively effect parasites, making it more difficult for them to parasitize the fish. However, 1.018 will not kill the parasites, just slow them down.

2. Increase oxygen levels of the water. Not sure how important this is, as 1.025 typically has plenty of oxygen also, as long as there's good flow and surface disturbance.

3. Lower salinity levels do make it more difficult to keep a stable pH.

[Fizz71]

I had read that even 1.010 to 1.013 is considered "hyposalinity" and would result in the death of ich, and aptasia as well as starfish, cucumbers, anemones (that we want), urchins, feather dusters, etc.

LFSs keep it low because it's cheap too, since they go through a boat load of water.

Anyway..me personally I wouldn't drop below 1.023 even if I were running a FO tank, just because I'd be concerned about the fish long-long term. But I wouldn't run it up at 1.026 like I am now either.

[sslak]

I run 1.026 as I've read that's close to natural seawater.

I've never taken my refractometer to the ocean...although maybe I'll pack it for my next vacation! :beachbum:

I bet the girls on the beach would give me some strange looks if I started taking readings...LoL.

[jason2459]

I run 1.026 as I've read that's close to natural seawater.

I've never taken my refractometer to the ocean...although maybe I'll pack it for my next vacation! :beachbum:

I bet the girls on the beach would give me some strange looks if I started taking readings...LoL.

Eh, who cares about the girls on the beach. You got pods in the sand to get.

[mr.maroonsalty]

The big thing that hyposalinity does, is taking stress off the metabolic demands fishes have expelling salts, freeing their body's systems up to take care of the other stresses put on them by going from the oceans, through the sometimes numerous handlers to our tanks.