Mixing time, Red Sea Coral Pro, and Precipitation Plausable? Mythbuster style

[jason2459]

I wonder if that's what happened to me.... or maybe I added it all too fast.
I have a 20H aquarium as my new salt water reservoir. I poured about 15 gallons of room temperature RODI water, placed a powerhead in and added about 7 1/2 cups of salt, one cup at a time. I just dumped the cups in, didn't swirl or let the salt trickle in. I left the pump running for about 8 hours- milky water. It cleared in about 3 days leaving a tan film on the powerhead and bottom of the tank.

I don't like to dump all in at once in one spot. I generally shake the salt over the entire surface over a period of time. It's not a long period of time but don't know how long exactly it is. I use a full 50 gallon bag at a time in a 55 gallon container and have the low and high level points set so 1 bag added will bring salinity to 35ppt.


However for this test I dumped in all the salt at once like in the video into that 5g bucket.

 

[USMC4Life]

I wonder if that's what happened to me.... or maybe I added it all too fast.
I have a 20H aquarium as my new salt water reservoir. I poured about 15 gallons of room temperature RODI water, placed a powerhead in and added about 7 1/2 cups of salt, one cup at a time. I just dumped the cups in, didn't swirl or let the salt trickle in. I left the pump running for about 8 hours- milky water. It cleared in about 3 days leaving a tan film on the powerhead and bottom of the tank.

Well I do it the same way. I do about 4. 12oz cups per 20g of water that I change out at a time. If I need more then I just dump it in. I never do it slow. I just take measurements after about 10 min to see where I am at. And add as needed.

 

[jason2459]

6pm 12 hours at 115. Bumping up to 120

Some precipitation on heater. Water clear

 

[jason2459]

6am 12 hours at 120. Water is clear but as expected pump is rattling bad and heater is getting coated in precipitation.

So, Busted.

Going to watch the video again.

Come back later tonight and in mytherbuster style force a precipitation snow storm. Failure is always an option.

 

[jason2459]

So, was thinking of just pouring in some limewater.... lets see what happens.

 

[jason2459]

So, I set the heater this morning to 77F. Tonight its still at 84F


Added 36oz of fully saturated limewater

Ok....

Added some salt mix to bring back up to 35ppt

I let that mix for 30 minutes.

Hmmm... a little cloudy

Not cloudy enough!

Added some CaCO3...

Now THAT'S cloudy.

Watching the video I have a feeling that wasn't 12 hours based on fish movement

And have a feeling something external to the pump, water, and saltmix that was initially put in caused the cloudy water.

Why they would rig that I have no idea or if they really did. They may not really know why it did what it did if they didn't purposefully cause it.

But precipitation certainly did happen by the end of this. My pump was near seizing and heater was getting encrusted. My hypothesis was right.

Alk at the end before adding limewater was 11.8dkh. Close enough for error and good enough to believe there was a drop. But I had to really try to get that to happen.

Sorry, I don't have the alk numbers after adding the limewater. I didn't think those numbers mattered so much as it was purely to try and force an event. Not something normally done to new saltmix. Also, I'm tired and heading to bed now.

 

[Randy Holmes-Farley]

Thanks for doing these studies.

 

[USMC4Life]

Busted!!!

 

[jason2459]

lol yeah

Welcome Randy it was interested.

 

[Randy Holmes-Farley]

Any idea what the pH is of this salt when first mixed but not aerated much? Some in the past had pretty high pH, which would accelerate precipitation until it brought in CO2.

 

[jason2459]

Any idea what the pH is of this salt when first mixed but not aerated much? Some in the past had pretty high pH, which would accelerate precipitation until it brought in CO2.

No, I'm sorry I don't. My pH pin has died. Had it for many years too. Need to get another. I was only recording Alk, Temp, and Salinity.

 

[Larry L]

I'm curious if it makes a difference if you keep the mixing bucket covered vs uncovered while you do this. Seems like doing it uncovered would mean the air CO2 levels might have ore of an effect.

 

[jason2459]

I'm curious if it makes a difference if you keep the mixing bucket covered vs uncovered while you do this. Seems like doing it uncovered would mean the air CO2 levels might have ore of an effect.

Since there's nothing in the water to drive anything that would drive CO2 up I'm not sure it would make much of a difference. To add the lid was just resting on top with gaps where cords went through.

 

[jason2459]

Oh yeah, and that pump pretty much was useless after this testing. [emoji1]

And I got a new pH pen since then.

 

[Fishresponse]

I've had the cloudy precipitation event myself. Can't say what I did differently than what you did. I switched salts since then so haven't encountered this but will do a couple tests myself to check so I don't get any precipitation. Great experiment!

 

[Randy Holmes-Farley]

A couple of followup comments on this thread...

1. It just occurred to me one possible reason Red Sea Coral Pro might have more of an issue with precipitation than other high alkalinity mixes (and certainly the high alk is the biggest issue). In another thread I'm debating with someone whether this should be called real seawater since it comes partly (72%) from dried seawater. Ignoring the semantic issue, the fact that it comes from dried seawater means it must have calcium carbonate crystals already in it from the drying process, and those crystals might act as nucleating sites for precipitation that may otherwise have to first form in other types of mixes that also have high alkalinity (say, Reef Crystals).

2. Second comment relates to Red Sea's very strange wording to avoid aeration when mixing Red Sea Coral Pro, but it should be mixed until the pH stabilizes. pH "stabilization" would seem to involve and inherently require aeration of some sort. I wrote to Red Sea customer service and got back an answer that was simply incorrect chemistry:

"Mixing the salt with high agitation at the water surface increases the amount of Co2 that evaporates from the water causing an increase in both pH and alkalinity that enhances the chance of precipitation. "​

So I asked for the question to be forwarded to their Head Chemist to make sure it was the formal Red Sea explanation for the wording on the container. That was now more than a month ago, and no further response.

 

[Calpoly2103]

Hi All,

Sorry to wake up this old thread. I am planning on using RSCP water and purchasing it from a LFS. I was planning on buying enough water to last me for 2 weeks at a time, and doing weekly water changes. (This will limit my trips to LFS to 2x per month). I've read this whole thread however haven't been able to pinpoint if its OK to store the RSCP water in regular plastic 5G containers in the garage, until I need to use it.

Can anyone comment? Thanks !

 

[badams.one]

Oh yeah, and that pump pretty much was useless after this testing. [emoji1]

And I got a new pH pen since then.

Hey bud, appreciate all the effort and details you provided on this. I see that there is no issue with this salt getting to really high temperatures, but am curious if you were to initially mix this salt with RO water at higher temperatures, say 85/90 degrees. During the summer my garage gets pretty hot and often times I find myself mixing salt in RO water in that range. I've had issues with other brands of salt and am curious how this salt would be affected. Do you by chance have any information on that specifically? Appreciate it!

 

[jason2459]

Hey bud, appreciate all the effort and details you provided on this. I see that there is no issue with this salt getting to really high temperatures, but am curious if you were to initially mix this salt with RO water at higher temperatures, say 85/90 degrees. During the summer my garage gets pretty hot and often times I find myself mixing salt in RO water in that range. I've had issues with other brands of salt and am curious how this salt would be affected. Do you by chance have any information on that specifically? Appreciate it!

Sorry, late reply. Life's been super busy past several years.

I assume you've either experienced an issue or didn't? I'd love to hear either way.

I personally would just add the salt relatively slowly and not dump in a lot at once especially at the elevated temps.