Whats your sg level?

[Reefugee]

Mike,

Curious how you got the auto topoff for that cheap? I recently quoted a friend a price of $50 in parts for an auto topoff system - and that doesn't include pumps.

Float switch (2) $14 (you could build with one switch, but I like safety shutoff)
Relay (1) $10
Powersupply $10
Project box $3
Connector $2
Power output $5
Misc parts $3.

But I agree with you - the peace of mind (or conveniences) is priceless! I am building an auto topoff for my nano now. (Yes - I am that lazy.)
Minh

 

[JeffReef]

<a href=showthread.php?s=&postid=9200917#post9200917 target=_blank>Originally posted</a> by Unarce
I admittedly let mine get up to 1.027 at times, but only my clams have a reaction to that. Everything is fine.

The average of the world's oceans is actually 35ppt, which converts to 1.026. Some areas, like the Red Sea, have extreme SG and temp fluctuations, and will get up to 1.030. This is why the fish from there are so damn tough. Hopefully one day, we'll be able to get coral from there.

I've been running my sg at 1.030 for more than 10 years without a problem on my fish and soft corals. I had a stupid theory about this when I first started reefing and it just stuck with me for all those years.

I just started placing SPS in my tank and 2 out of 4 SPS frags started bleaching. I'm not sure if high SG was the cause but it's possible.

 

[jacmyoung]

<a href=showthread.php?s=&postid=9200917#post9200917 target=_blank>Originally posted</a> by Unarce
I admittedly let mine get up to 1.027 at times, but only my clams have a reaction to that. Everything is fine.

The average of the world's oceans is actually 35ppt, which converts to 1.026. Some areas, like the Red Sea, have extreme SG and temp fluctuations, and will get up to 1.030. This is why the fish from there are so damn tough. Hopefully one day, we'll be able to get coral from there.

That was my question, are 1.026 and 35ppt temperature dependent?

Regardless, should an auto-temp-correct refractometer report accurate sg regardless your water temperature?

 

[mpoletti]

1.025-1026 depending on how close I maintain my topoff. My temp is 78 in the morning and 80 at the peak of my haildes.

 

[funman1]

That's what I thought too??
I read the same when my water change water is cold or at 80?

<a href=showthread.php?s=&postid=9201631#post9201631 target=_blank>Originally posted</a> by jacmyoung
That was my question, are 1.026 and 35ppt temperature dependent?

Regardless, should an auto-temp-correct refractometer report accurate sg regardless your water temperature?

 

[boviac]

50 gal soft/LPS ran about 1.023-1.025 before refractometer and with one now I run 1.025 with a Kalk drip makeup. Temp ranges from 76-81 depending on the time of year (ACII).

 

[fishsoldseprtly]

1.025 @ 79F refracto

 

[Dave E]

I did a test after I installed my refugium and found I was losing about 1.5 gallons every day.

I tested SG every morning for a week at 5:00am before work and it would be at 1.025 using both a refrac. and a hydro. Temp @77.5 digital thermo.

Tested again 7:00pm before topping off and SG would be at 1.026 with Temp at 79.2 I would also check 10min after topping off and it would be back at 1.025 SG.

Dave

 

[robertloop]

1.024, Refract....... 80F average.

 

[dots]

<a href=showthread.php?s=&postid=9201114#post9201114 target=_blank>Originally posted</a> by MrMikeB
1x Mechanical float valve - $20
1x cheap aqualifter - $20
1x 5 gallon bucket - $3
5' 3/8" tubing - $1

Peace of mind with a DIY top-off system - priceless!

A bunch of crap laying in your living room, where your girlfriend already has to look, listen, and smell:

skimmer
chiller
misc electrical wires
all because "this is all a temporary living situation"

adding more until I move is just plain DANGEROUS..........

when I move, I plan on getting a low iron cube fully controlled with plumbing in the "spare" bedroom or an insulated spare "closet" in the garage to hide in.

 

[dots]

I just checked mine and it rises to 1.0245 at the average point of daily evaporation.

I suppose the whole point of this thread is.......given I am at 1.023 and have an SPS only tank, could I benifit with better coloration or growth by upping it to 1.025, or would I be taking an unecessary risk by pushing the limit and end up RTNing stuff........based on the current trend it would rise daily to 1.065 and then possibly more if something happens and I cant get to it.

Karl, whats your opinion on this considering your in the same risk factor as I am and seem to be "pushing" it admitly sometimes?

Is the benifit worth the risk of potential mishap?

 

[Unarce]

Doug,

For SPS, I wouldn't worry too much about it. If it's a gradual SG change from 1.023 to 1.025 over a 72 hour period, you'll be fine. It's just a different story when it comes to maxima clams. Whole different beast there.

Then again, if it ain't broke, don't fix it. I don't think it's going to have much effect on coral color.

HTH

Karl

 

[dots]

You know the story, trying to dial it all in and get closer and closer to "perfection" and ideal condiitons to make the sticks color up good and sprout.......

Speaking of coloring up.......holy cow......I have been trying to get a pic of that digi for you, but even on a good day the blue is so much paler than the danae that its hard to show with the camera.
Though not as popular as some......its still one of my favorites!!!

Overall though, since I got the nerve to feed more without the fear of browning everything in the process, (after some guy in a LFS berated me about "starving" my corals.....well ok he was right, maybe he does know what he is talking about afterall), coloration and growth have taken off......

thats the reason for all of this, I am second guessing everything and dialing it all in......redid some of the rock again and am messing with the flow a little......I think it helps overall to adjust the flow every couple of months if you don't have a mover or wave timer.

Thanks for the input everyone!!!!

 

[JTEAGUE]

1.026 to 1.027 and the temp ranges from 78 - 81

 

[Reefugee]

ATC is more of a marketing ploy than anything else. If you look at these refractometers, they work in a relatively narrow band of temperature (50F/10C - 86F/30C). I did a google search and found that the density of water at various temperatures:

Temp. Density (kg/m^3) Specific Volume (m^3/kg) (calculated)
10C 50F 999.8 0.0010002
15C 59F 999.2 0.0010008
20C 68F 998.3 0.0010017
25C 77F 997.1 0.0010029
30C 86F 995.7 0.0010043

If my calculation is correct, kg/m3 is the same as g/l. Anyway - salinity of ocean is 35 psu - which by definition means exactly 35 grams of salt per liter of water. So let's see what happens when we go from from 10C to 30C in solution. Lets assume we have 35 PSU at 10C and heat it up to 30C.

Assuming we have exactly 1 L of water and exactly 35g of salt, we would have a reading of exactly 35PSU. (I think PSU is similar to PPT) Increase the water to 30C, the volume of the water would increase by 0.23% [ (0.0010043-0.0010002)/ 0.0010002 x 100% = 0.23% ] or 1.0023L. Since the amount of salt has not changed, the new salinity is 35g/1.0023L = 34.92PSU . The water temperature change caused the salinity to change 0.23% [ (35-34.92)/35 * 100% = 0.23%).

Just looking at some of the refractometer out there, they have an accuracy of +/- 1ppt or accuracy of 0.2%. Remember - this is when the refractometer is calibrated at 20C, and I calculate the error over the whole range. So even with the changes in salinity caused by the temperature change within the refractometer temperature range - the refractometer is still reading within it's accuracy.

Conclusion: ATC is a bunch of marketing hype. Within the operating range, the refractometer is still within an acceptable error range. Regardless - a refractometer still works great!

Minh

PS - I used PSU instead of PPT because PSU is easier to calculate. I just want to show how the salinity changes very little over that temperature range.
PSS - for you science buff - I ignored significant figure in the calculation. If I had to to illustrate the insignificant changes.

<a href=showthread.php?s=&postid=9201631#post9201631 target=_blank>Originally posted</a> by jacmyoung

Regardless, should an auto-temp-correct refractometer report accurate sg regardless your water temperature?

 

[Reefugee]

double post

 

[jdieck]

<a href=showthread.php?s=&postid=9198612#post9198612 target=_blank>Originally posted</a> by FoothillCorals
Why dose everyone keep it so high? I have allways ran it around 1.023-1.024 @ 79.

Natural sea water is at 1.0265 (35 ppt)

I keep it also at 1.026-1.027 79*F Refractometer.

 

[jdieck]

Refugee:

I understand that the temperature compensation is to correct the refractometer variations with temperature not really the water.

 

[Reefugee]

Jdeieck,

I might be wrong, but I am pretty sure that they are talking about the temperature of the solution and not of the refractometer. Granted, the temperature of the refractometer will affect the temperature of the solution once you put it on the glass. But I am sure you are interested in the temperature of the liquid.

Minh