1.025 vs 1.0264 Which Is Which?

[LarryS]

Why is there so much confusion and conflicting advice over the recommended specific gravity of the saltwater for keeping reef?

My LFS says go with 1.025. Lots of reputable sources on the web say go with 1.026 (1.264 or 35 PPT to be exact).

Many users here target 1.025.

And Reef Crystals' salt instrucrions recommend a range of 1.020 to 1.023 at 75 degrees. Well, that's great but if you're using a refractometer that auto temp adjusts, then what? Not to mention their target not in the range of 1.025 or 1.026.

 

[Unicorn]

1.025 and 1.026 is not as big of a difference than 1.020 or 1.023! When water in ur tank evaporates than ur level is gonna swing from 1.025 to 1.026 anyways until u add fresh water again
1.025 is a save area for fish and corrals if you calculate the swings in
yes, the refractometer Doesn't mark that 1.025 and 1.026, but 1.025 is still better visible with that bigger line

 

[joy13]

I go with 1.025 for my tanks. As long as it is stable at one or other it will be fine.

 

[ccCapt]

I keep mine at 35 ppt.

Ron Shimek's Website...Critters
"Coral reefs are generally located in areas that have salinities in the range of 35 ppt (1.026) to 38 ppt (1.029). Most of our corals, and the associated fauna including fishes, will live best at those conditions (Weber and White 1976)."
"The bottom line for salinities is simple. There is simply no reason at all to maintain the salinities of our systems below normal reef conditions. All reef inhabitants will suffer damage from prolonged exposure to lowered salinities. Invertebrates kept at low salinities often die within a few days to a few months. Given that corals, sea anemones, sponges and some other invertebrates have no old age or senescence (or to put it another way, they are immortal), low salinities result in a quick death. Some mollusks, crustaceans, and most fish kept at low salinities die of kidney failure; it just takes them longer. A fish which dies in a couple of years in a hyposaline aquarium may have had the potential to live more than 20 years had the salinity been appropriate."

 

[LarryS]

I keep mine at 35 ppt.

Ron Shimek's Website...Critters
"Coral reefs are generally located in areas that have salinities in the range of 35 ppt (1.026) to 38 ppt (1.029). Most of our corals, and the associated fauna including fishes, will live best at those conditions (Weber and White 1976)."
"The bottom line for salinities is simple. There is simply no reason at all to maintain the salinities of our systems below normal reef conditions. All reef inhabitants will suffer damage from prolonged exposure to lowered salinities. Invertebrates kept at low salinities often die within a few days to a few months. Given that corals, sea anemones, sponges and some other invertebrates have no old age or senescence (or to put it another way, they are immortal), low salinities result in a quick death. Some mollusks, crustaceans, and most fish kept at low salinities die of kidney failure; it just takes them longer. A fish which dies in a couple of years in a hyposaline aquarium may have had the potential to live more than 20 years had the salinity been appropriate."

Very interesting stuff, Larry. Nice to have some science behind the numbers. This along with the links is very useful stuff! BTW, your tank and stand builds are awesome.

Staying on topic, can you recommend any specific literature (in general) for less experienced hands... but who want a complete guide to proper setup and maintenance....that's up-to-date... recipes, etc and how-tos for keeping things on track... so much I've looked into seems lacking or very dense.

 

[ccCapt]

You can find just about anything you want or need to know here....
Reef Chemistry Articles - Reef Central Online Community Archives

 

[melosu58]

I agree with Larry. Those are good links he gave you. I keep mine at 1.026 as this is supposed to be where Natural sea water is at.

 

[LarryS]

You can find just about anything you want or need to know here....
Reef Chemistry Articles - Reef Central Online Community Archives

An awesome archive. Thanks!!

 

[LarryS]

I agree with Larry. Those are good links he gave you. I keep mine at 1.026 as this is supposed to be where Natural sea water is at.

Yes. I was just now perusing them... almost a bit overwhelming but also well organized and cataloged.

I was also hoping to find something authoritative on fishless cycling but didn't come across it.

Any ideas?

 

[matthewh133]

Really odd, so much conflicting info. I was also told 1.025 by my LFS. They said their natural salt water comes in at 1.027 so to add a little RO water with it. Mine's currently at 1.026.

 

[LarryS]

Temperature

As a follow-up to the NSW target for salinity 1.026 and given the observations and data that Dr. Shimek also presented on the temperaturevariances, reproductive health, etc. from locale-to-locale and seasonality within specific reef systems, getting to an "optimum" temp in a home reef almost seems more problematic.

Temperature and Salinity in Maintaining Coral Reef Aquarium Animals Ron Shimek's Website...Critters

Since we're referencing NSW observations and data, I'm thinking we're not too far off topic here.

What is the ideal target temp? 78F is what my LFS recommended.

 

[tlkng1]

I sit at middle range around 75. For many species of critters that I have, the optimum range is 72-78. To me, sitting at 78 means a constant balancing act on the edge.

 

[ccCapt]

From the Ron Shimek article...
"The average temperature calculated for all 1000 + coral reefs was 81.7°F. Over all reefs, the average lowest temperature observed was 76.4°F, and the average highest temperature was 86.4°F. One way that these data could be interpreted would be to say that for most corals and coral reef animals, the best conditions would be between 76°F and 86°F, with the average being about 82°F."

I have my temp controller set to kick on the heaters if the water drops below 80 and the fans kick on if the temp goes over 82. When I was running metal halides my temp would vary between 80 (lights off) and 82 (lights on). Now that I'm running LED's my temp is pretty solid at 80.

 

[LarryS]

I sit at middle range around 75. For many species of critters that I have, the optimum range is 72-78. To me, sitting at 78 means a constant balancing act on the edge.

Very interesting approach. I've also noticed using 78 as a 'baseline' seems to encourage temp rising during that day - granted, I'm still cycling but we've been in some mild weather (60-80 daytime) so it's easy to see how this might be problematic in warmer weather. Evenings/nighttime heaters work like champs.

 

[LarryS]

From the Ron Shimek article...
"The average temperature calculated for all 1000 + coral reefs was 81.7°F. Over all reefs, the average lowest temperature observed was 76.4°F, and the average highest temperature was 86.4°F. One way that these data could be interpreted would be to say that for most corals and coral reef animals, the best conditions would be between 76°F and 86°F, with the average being about 82°F."

I have my temp controller set to kick on the heaters if the water drops below 80 and the fans kick on if the temp goes over 82. When I was running metal halides my temp would vary between 80 (lights off) and 82 (lights on). Now that I'm running LED's my temp is pretty solid at 80.

LEDs will certainly make temp regulation easier by not adding heat. The Ron Skimek article certainly makes the case for keeping the baseline at 80, of course fans still required on warmer days.

Have you seen any references (like Shimek's) for fish only tanks?

 

[ccCapt]

In regards to a fish only tank, what fish do you have in mind that don't live on a reef? Very few fish in the marine aquarium trade don't come off reefs.

 

[LarryS]

In regards to a fish only tank, what fish do you have in mind that don't live on a reef? Very few fish in the marine aquarium trade don't come off reefs.

Still sorting that out. I gleaning from your comment that I can target the same temp unless noted elsewhere in the reference (requirement) of that fish.

That said, not sure that of the books I'm perusing (including Scott Michael's field guides) that I noticed how to differentiate between those fish that come off reefs and those that don't. Just assumed (apparently in error) that a non-reef safe fish was not from the reef.

Frankly, offhand I'm not recollecting any special references to temp (or salinity unless fresh or brackish fish).