Is this a debate: 1.025 vs 1.026 specific gravity???

[chrisbenavides]

I have heard many saying that 1.025 should be the sg of a tank, while at the same time I have heard just about many saying that 1.026 is better (like the ocean).

Also, why do liveaquaria and marinedepotlive say we should keep our fish to as low as 1.020 to 1.025? Is not 1.020 too low (compared to the ocean).

What affects do fish and corals get when the salinity is too low or when it is too high? Are there any benefits to a certain salinity?

What specific gravity do you have your tank?

[SweetFawn]

Mine has been a constant 1.023.

[BLOODMAN]

1.024

[bertoni]

I think the canonical "average natural waters" is around 1.0265. So I target 1.026. How tolerant animals are of deviations from that level depends on the animal in question. I'm not sure there's any evidence that 1.025 is going to do any harm over the long term.

[chrisbenavides]

hmm... so for your common reef fish (clowns, basslets, tangs) with your common LPS and softies corals.....would 1.025 be bad or not much is known on this subject.... Would high salinity be bad and does it actually lower parasites in the tank???

Do people actually keep there sg at 1.020 is stores suggest?

[bertoni]

I doubt 1.025 is going to be a problem for fish. I doubt that it's a problem for corals, either. There's no real data, though, on that small a difference, AFAIK. I wouldn't worry.

[vince R]

1.025 here.

[yoboyjdizz]

Originally posted by chrisbenavides
hmm... so for your common reef fish (clowns, basslets, tangs) with your common LPS and softies corals.....would 1.025 be bad or not much is known on this subject.... Would high salinity be bad and does it actually lower parasites in the tank???

Do people actually keep there sg at 1.020 is stores suggest?

high salinty dosen't lower parasites, for fish treating them for parasites you wanted it to be lowered where the specific gravity is of 1.009 for 3-6 weeks ( but only do this in a quarantine tank since lower salinty levels are deadly to inverts and coral ) live rock will be safe but you will be killing any organism living on it.. i believe a good 1.023-1.026 is where you want to target your levels

[jmack]

My problem with trying to keep it at 1.026, is that when evaporation occurs there is an increase in salinity. So, I try to keep it at 1.025 so that when it does evaporate, it doesn't get too high.

[tangwang]

Originally posted by jmack
My problem with trying to keep it at 1.026, is that when evaporation occurs there is an increase in salinity. So, I try to keep it at 1.025 so that when it does evaporate, it doesn't get too high.

How much does your tank evaporate in a day? Should be little or no rise as long as you keep it topped off daily in a 120g...

[bertoni]

It doesn't really seem to matter. SG going a bit over 1.026 isn't any more dangerous than going over 1.025, IME.

[jmack]

It seems like I'm getting quite a bit of evaporation..I definitely notice a difference since I got the PC's. But the SG has risen to 1.027 which I thought was harmful.

[Amphiprionocellaris]

Stability, stability, stability.
The important thing with SG is stability (within a range, of course). I keep one reef at 1.023, one at 1.027, one between 1.026 and 1.025, and one at 1.025 (I actually measure salinity in ppt, not specific gravity, but they are pretty interchangeable). All of these reefs have had equal success, so I say that IMO maintaining what measurement you've got is better than spending a lot of time and stress (for you and your tank) trying to get a specific value.

[bertoni]

No way. I've run tanks for weeks at 1.027. That's well within the normal range. Some of the tanks have gone over 1.030. Only the refractometer knows for sure. :)

I don't advocate that kind of stress; those were small tanks without any valuable corals in them, and I wasn't very healthy at the time.

[Amphiprionocellaris]

Hmm, that's confusing...I think I replied right when bertoni did. I believe his reply is to the post above mine, not mine. That line of thought seems to flow a little better.

[bertoni]

We were at almost the same time, so, yes, my response was to the post before yours.

[gtriamy]

i keep my tank at 1.020, keeps the ick away, doesn't hurt any of my livestock

[greenbean36191]

i keep my tank at 1.020, keeps the ick away, doesn't hurt any of my livestock
Keeping sg that low is hurting your inverts whether they have started to show it or not. The chemistry in their bodies has adapted over millions of years to function under certain conditions and if you go outside of that normal range it causes them conciderable stress. Their metabolisms go haywire because some chemical reactions in their bodies slow down or even stop working. It can also cause tissue damage as cells swell or shrink due to osmosis. Usually snails and echinoderms are the first to show problems at about 1.024 and lower. They can take a long time from the initial onset of damage to actually show problems though.

Also, there is no evidence to suggest that a salinity of 1.020 has any positive effect on the number of parasites.

[sjm817]

Originally posted by chrisbenavides
I have heard many saying that 1.025 should be the sg of a tank, while at the same time I have heard just about many saying that 1.026 is better (like the ocean).
Splitting hairs IMO.

[rjwilson37]

I do like jmack say's. I keep my tank at 1.025 to 1.026. I do a water change and if the tank is at or close to 1.026, I will get it back down to 1.025, because it will creep back up to or near 1.026 it seems even with my top-off during the course of the week. It is not that stressful at all to your fish for the salinity to lower by .001 or even by .002 during a water change, it is when it goes up where it can have an effect on them. I never like it to deviate by more than .001 during the course of the week and typically bring it down by .0005 or a maximum of .001 during a water change.

I use a refractometer that I calibrate every so often to make sure it is accurate.

[rjwilson37]

The reason why I am so careful is that I run my tank temp. at 81 to 83 which can make things go wrong a little quicker if there is a problem. The fish are a lot more active at higher temps. as well as a bit more sensative to changes in things like salinity more so than it can at lower temps where they are not as active. The fish stores like to keep things at lower temps, especially bringing new reefer's into the hobby, because this makes things happen a little slower. By things happening a little slower, it give you more time to react to a situation.

Good things happen slowly in this hobby, you have to give your tank time to become something beautiful, where bad things can happen pretty quickly in this hobby.