Does Bacteria grow faster in higher salinity?

[Miami Reef]

Higher temper like 80F can speed up curing and bacteria reproduction. Which means the beneficial bacteria can outcompete algae in less amount of time.

What are the effects of 80F for corals? I read a study done that found corals in Red Sea resist bleaching due to higher salinity even when exposed to the global warming effects.

If I turn my temp to 80F should I worry about corals bleaching and in turn raise my salinity to 1.027-1.028?

I know it’s a super loaded question, but I really want to learn more about reef maturity in slightly higher temps.

 

[Danroo]

Higher temper like 80F can speed up curing and bacteria reproduction. Which means the beneficial bacteria can outcompete algae in less amount of time.

What are the effects of 80F for corals? I read a study done that found corals in Red Sea resist bleaching due to higher salinity even when exposed to the global warming effects.

If I turn my temp to 80F should I worry about corals bleaching and in turn raise my salinity to 1.027-1.028?

I know it’s a super loaded question, but I really want to learn more about reef maturity in slightly higher temps.

I would suggest keeping the temperature around 77 and salinity around 1.024-1.026. Not more than that. Bacteria will flourish in these conditions as well.

 

[Miami Reef]

I would suggest keeping the temperature around 77 and salinity around 1.024-1.026. Not more than that. Bacteria will flourish in these conditions as well.

That’s how my tank is now! I’ll keep it like you said because I really don’t know the true effects of higher salinity and temp. I know it can lower oxygen which is not good!

 

[DrZoidburg]

Macna vid out there talks a bit about this. Lower salinity raise temps. Higher salinity and the bacteria have to divert more energy into maintaining their cell walls. Also red sea has a higher salinity than other places our corals come from so that part could be true.

 

[Danroo]

That’s how my tank is now! I’ll keep it like you said because I really don’t know the true effects of higher salinity and temp. I know it can lower oxygen which is not good!

It really isn’t my advice. It’s from mr saltwater tank( who’s been in reefing since he was a kid and is now making tanks for clients). He mentions of your salinity goes above to 1.027 do a water change to bring it down to 1.024. With temperature he just says you can keep it around 80f. It’s pretty hot nowadays so my tank is in the same 80f.

 

[Acrofiend]

This was a snapshot I took from Dr. Tim’s talk for tips to speed up the cycle. This was for the bacteria that convert ammonia to nitrite. Not sure if it’s the same for all.

 

[Azedenkae]

This was a snapshot I took from Dr. Tim’s talk for tips to speed up the cycle. This was for the bacteria that convert ammonia to nitrite. Not sure if it’s the same for all.

It's a good talk to watch to get an overall sense of what we should expect from nitrifiers, broadly. I think it is good advice to follow.

In reality, nitrifiers vary wildly in terms of what parameters they are best adapted to. That's also why we have 'freshwater' and 'saltwater' nitrifiers for example, although one study did find saltwater nitrifiers to do pretty well in lower salinities, but not vice versa.

This study here might be of interest to us in particular: https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijsem.0.002416. One species was collected from a marine fish tank, though the paper did not specify where (water, sediment, rocks, etc.) though if I was to hazard a guess, probably the water. Their optimal salinity for growth do vary, but is between 25ppt and 37ppt, or 1.0188 to 1.0279 sg, if my conversions are not incorrect. The marine aquarium species in particular has optimal growth rate between 1.0241 to 1.0279 sg, which is well, the range our aquariums are at, rather than the lower temperatures for the nitrifiers mentioned by Dr. Tim.

It is possible, and probably likely, that it is a simple matter of 'natural' selection happening and the organisms best adapted to our aquariums will prosper, while other ones will perish or at least diminish in numbers.

 

[Randy Holmes-Farley Verified Community Expert]

I do not know any reason to think higher salinity than normal reef salinity will boost bacterial growth rates and accomplish what you are asking about.

I'm also not sure what you mean by beneficial bacteria outcompeting algae (for what?), and I would not assume higher temps will make that more likely.

 

[Reef and Dive]

They grow faster in lower salinity

 

[ReefRusty]

What about using straight forward Natural sea water this is 1.027-1.028 I've been using it and used to run my tank at lower salinity of 1.025 but introducing RODI water to lower my salinity also lowered my Mag from 1290 down to 1150 and calcium from 420 to 350 plus the fact Alk was 7.1 with NSW lowering it down to 6 meaning I was always dosing these to raise them back up. This cased me to go through bottles and bottles of each one to maintain a reasonable level.

So made the switch and don't import RODI water and use my collected NSW at 1.027.

Have not really seen any effect on corals and or fish buy having a higher salinity level. Maybe growth rates of corals have slowed down but everything appears to be happy.

 

[Randy Holmes-Farley Verified Community Expert]

What about using straight forward Natural sea water this is 1.027-1.028 I've been using it and used to run my tank at lower salinity of 1.025 but introducing RODI water to lower my salinity also lowered my Mag from 1290 down to 1150 and calcium from 420 to 350 plus the fact Alk was 7.1 with NSW lowering it down to 6 meaning I was always dosing these to raise them back up. This cased me to go through bottles and bottles of each one to maintain a reasonable level.

So made the switch and don't import RODI water and use my collected NSW at 1.027.

Have not really seen any effect on corals and or fish buy having a higher salinity level. Maybe growth rates of corals have slowed down but everything appears to be happy.

If you used RO/DI water to lower natural seawater salinity and found magnesium and calcium dropped that much, then you either lowered it too far (aim for sg = 1.0264, or 35 ppt), or one or more of the several measurements you made is off.

 

[Casket_Case]

I’ve always kept my tank at 79° F 80° F and salinity at 1.023 to 1.024 so high temp but lower salinity. My tank is supposed to be like the Florida Coast which is high temperature and low salinity.

 

[Randy Holmes-Farley Verified Community Expert]

I’ve always kept my tank at 79° and salinity at 1.023 to 1.024 so high temp but low salinity. My tank is supposed to be like the Florida Coast which is high temperature and low salinity.

Salinity varies a lot in Florida, and is not always low.

 

[Casket_Case]

Salinity varies a lot in Florida, and is not always low.

Where I used to hang out in Florida when I lived there the salinity was WAY low and the temperature was WAY high way higher than I’m comfortable with lol. It was like brackish and it was 86° F but I’m not doing that drastic so my tank conditions are just slight nods to that.

 

[ReefRusty]

If you used RO/DI water to lower natural seawater salinity and found magnesium and calcium dropped that much, then you either lowered it too far (aim for sg = 1.0264, or 35 ppt), or one or more of the several measurements you made is off.

I always aim for 1.025-1.026 or more 35pt using refractometer. Lowering it down. 002 affects the change in mag cal and alk by lowering it have done multiple tests resulting in same

 

[Randy Holmes-Farley Verified Community Expert]

I always aim for 1.025-1.026 or more 35pt using refractometer. Lowering it down. 002 affects the change in mag cal and alk by lowering it have done multiple tests resulting in same

nevertheless, something in the measurements is off.

The difference between a sg of 1.025 and 35 ppt is substantial with respect to ions such as calcium (a difference of 22 ppm) or magnesium ( a difference of 68 ppm), but natural seawater at a sg of 1.025 will have both calcium (398 ppm) and magnesium (1212 ppm) substantially higher than you report.

 

[DrZoidburg]

nevertheless, something in the measurements is off.

The difference between a sg of 1.025 and 35 ppt is substantial with respect to ions such as calcium (a difference of 22 ppm) or magnesium ( a difference of 68 ppm), but natural seawater at a sg of 1.025 will have both calcium (398 ppm) and magnesium (1212 ppm) substantially higher than you report.

I think he was starting with 1.027-1.028 though.

 

[Randy Holmes-Farley Verified Community Expert]

I think he was starting with 1.027-1.028 though.

Let's back up.

First statement from him was that diluting the seawater from 1.027-1.028 to 1.025 lowered mag and calcium too much.

My response was he either lowered the salinity too much (that is part of the issue, he lowered it too much and went lower than 35 ppt, so must expect cal and mag to be much lower than normal), or some measurement was off (that is likely also partly true).

The rationale for the measurement off issue is that seawater with a sg of 1.025 will have calcium of 398 ppm and magnesium of 1212 ppm. Both values are substantially higher than he reports.

Thus, the drop he saw was partly the expected drop when lowering salinity below 35 ppt, and partly from some sort of measurement issue (salinity or mg/ca).