Awc with high salinity storage to reduce footprint

[shoedy]

I'm new to reefing and I'm looking to build an auto water change system with a small footprint because it all needs to fit in my living room. I have 150 gallon tank, an RODI unit, apex & the dos and can do the plumbing from the RODI unit installed under the kitchen sink and to the drain there.

Ideally I'd like to keep the footprint of the fresh saltwater tank small and awc on auto pilot for at least 2-3 weeks. Is there anyone with experience who has a fresh saltwater tank with at a (way) higher salinity and put RODI+saltwalter in the sump at the same time?

A lot of questions;
If so, at what salinity do you keep your storage?
What kind of reduction in volume would I be able to achieve?
How do you manage salinity drifts?

 

[tzabor10]

I don’t know of anyone who does water changes that way. Following to see if this exists

 

[Doctorgori]

interesting concept …following
added: This might be a RHF thing ( chemistry forum maybe?)
anyway I’ve used up/abused my allotment of RHF summons,
someone else’s turn

 

[shoedy]

From what I've quickly derived from an online calculator I think I could potentially achieve a 3-4 fold reduction by mixing a concentrate fresh saltwater mix at whatever what is in my refractometers range (so that I can measure the concentrate). Or go even higher in the concentrate beyond the refractometers range and measure the result of the output (after adding more RODI water).

 

[Doctorgori]

From what I've quickly derived from an online calculator I think I could potentially achieve a 3-4 fold reduction by mixing a concentrate fresh saltwater mix at whatever what is in my refractometers range (so that I can measure the concentrate). Or go even higher in the concentrate beyond the refractometers range and measure the result of the output (after adding more RODI water).

yes, I would think you would have to use a dosing regime as opposed to a dumb ATO/evaporation thing…
Admittedly no clue how to calculate evap replacement using “brackish” water….KUDOS for even tackling this from this angle…fresh concept if you can nail down a formula

Again, maybe additional gray matter is needed here since your evap rate is variable with many inputs like surface agitation, ambient humidity, ambient room temps…I dunno if it’s doable given these variables

 

[Malum Argenteum]

I think Ca (and other elements?) will precipitate out at higher salinity.

 

[KStatefan]

I know Parkers Reef has talked about how he does it on a couple of his videos.

I think someone here is doing it also but can not remember who. maybe @Sisterlimonpot I know the subject came up in the Chemistry forum.

 

[shoedy]

Seems like we need a chemist to chime in here as well. I know BRS has done a test on storage at regular salinity levels which has proven that the main elements stay stable for prolonged periods when stored properly but I do not know what happens at higher salinity.

 

[JayM]

Easy in theory. 5 gallons of saltwater @ X salinity will need Y gallons of RO/DI to achieve 35ppt.
The hard part is figuring out which salt will reliably mix and store at your desired concentration, and how to ensure that the concentrate and the RO/DI will reliably mix in your DT without making anything unhappy. Plumbing RO/DI straight to the tank may also have issues related to TDS creep.

@Randy Holmes-Farley would know better than anyone.

 

[twentyleagues]

Depending on the sg you intend to mix to precipitation is a real concern.

 

[Sisterlimonpot]

I know Parkers Reef has talked about how he does it on a couple of his videos.

I think someone here is doing it also but can not remember who. maybe @Sisterlimonpot I know the subject came up in the Chemistry forum.

Yes, that's me...

I do mix salt to roughly 60ppt and dose it to beat the evaporation wall for dosing kalkwasser.

I made my own awc that has software that takes the gray matter out of the process.

I simply tell the awc what the premixed concentrated salt mixed to and it does all the calculations for me.

It's not suited for the application of lowering the salt storage container foot print. But the concept is basically the same.

Just off the top of my head though, the purpose as intended by @shoedy is to reduce the footprint of storage containers. The rub here is that whatever you're dosing from the concentrated salt needs to be offset by a precisely metered amount of rodi water, which will need to be in another storage bin.

With all that aside the math is pretty straight forward. If your target salinity is 35ppt and you dose 1L of RODI , you would need 1.4L of 60ppt to achieve 35ppt.

Concentrated Salt - Target Salinity = Delta Salinity

Target salinity ÷ Delta Salinity = Salinity Ratio

RODI in ml × Salinity Ratio = Concentrated Salt in ml

Example:

60-35=25

35÷25=1.4

1000×1.4=1400

Plug in any number for you concentrated salt, RODI and your targeted Salinity, and it will give you the proper amount of each to dose.

 

[KStatefan]

Yes, that's me...

I forgot about the kalk part.

 

[shoedy]

Yes, that's me...

I do mix salt to roughly 60ppt and dose it to beat the evaporation wall for dosing kalkwasser.

I made my own awc that has software that takes the gray matter out of the process.

I simply tell the awc what the premixed concentrated salt mixed to and it does all the calculations for me.

It's not suited for the application of lowering the salt storage container foot print. But the concept is basically the same.

Just off the top of my head though, the purpose as intended by @shoedy is to reduce the footprint of storage containers. The rub here is that whatever you're dosing from the concentrated salt needs to be offset by a precisely metered amount of rodi water, which will need to be in another storage bin.

With all that aside the math is pretty straight forward. If your target salinity is 35ppt and you dose 1L of RODI , you would need 1.4L of 60ppt to achieve 35ppt.

Concentrated Salt - Target Salinity = Delta Salinity

Target salinity ÷ Delta Salinity = Salinity Ratio

RODI in ml × Salinity Ratio = Concentrated Salt in ml

Example:

60-35=25

35÷25=1.4

1000×1.4=1400

Plug in any number for you concentrated salt, RODI and your targeted Salinity, and it will give you the proper amount of each to dose.

Thanks for the extensive explanation. I was considering going higher with the concentrate to 90-100ppm. Thank you for the math, makes sense and with ppt it is indeed straight forward.

I'm guessing getting the exact amount of RODI added is one of the more difficult parts as well as adding a flush valve if I want it to be plumbed in. One of my thoughts was to just use the ATO tank for this which already has a level sensor so I can let the plumbed in RODI just top this off. It would then take one extra DOS pump to take the RODI water and take care of adding the exact metered amount.

I'm in Amsterdam and unfortunately don't have the space to install big containers and my idea is to install like a 30 gallon tank hidden in a bench near the aquarium. This will last for >30 days based on my calculations with a 10% weekly change.

I wonder if the higher salinity will cause any other problems, like deposits on hoses and stuff. Will the DOS be able to handle it?

PS; I'm a software engineer so coding it won't be a problem. Did you do that on the APEX or are you using something else? And do you know if there's a way to interface with the APEX through an API?

 

[Reefering1]

100ppm sounds extreme. You can validate by mixing up a 5gal @100ppm and see if it precipitates within a month

 

[shoedy]

Time for a little lab experiment haha. ChatGPT says 70-80ppt is more sensible which would still be doable for my use case.

But wouldn't any brief stirring (blasting a powerhead) before taking anything out of the concentrate help with this?

 

[GARRIGA]

Only one way to know is a proof of concept on a Fishless smaller system. Can then test different salinity levels until it gets dialed in assuming over the coarse of a day evaporation remains the same. Won’t know exactly for the larger system but might derive a formula that would then be roughly applied. Granted evaporation can and will change throughout the year as house temps and humidity changes.

 

[TokenReefer]

And do you know if there's a way to interface with the APEX through an API?

I doubt it with the brand ecosystem these companies go for

 

[Sisterlimonpot]

I'm guessing getting the exact amount of RODI added is one of the more difficult parts

If you're going to use a peristaltic pump, and as long as they stay calibrated, it'll maintain salinity. The only time evaporation becomes an issue is if you run one peristaltic pump at a time. But if you run all 3 pumps simultaneously (concentrated brine, rodi and waste) then you won't disrupt the evaporation level.

I wonder if the higher salinity will cause any other problems, like deposits on hoses and stuff. Will the DOS be able to handle it?

As mentioned precipitation is your biggest concern. I've taken it to 70ppt without any visible signs of precipitation. I'd be curious what your experiment yields.

As for the DOS, I'm not 100% sure that would be the best option because of the way the software breaks up dosing with tdata. Ideally you want all pumps to run at the same time and I'm not familiar enough with DOS to know if that's possible.

I made my own arduino based awc that allows for easy programming based on what I mixed the concentrated salt to. I'm lazy and dump 2 bags of salt in roughly 55 gallons and whatever that mixes to (sometimes 60ppt, some thimes 65ppt) gets put into the awc. No more mixing to exact numbers haha.

Did you do that on the APEX or are you using something else? And do you know if there's a way to interface with the APEX through an API?

No this communicates with my diy kalk controller, and that communicates with apex in a very basic way.

Although, you might want to check github because there are some great patches into fusion. Some that mimic modules and also read data. For me that's far beyond my scope of expertise.

 

[Reefering1]

If you're going to use a peristaltic pump, and as long as they stay calibrated, it'll maintain salinity. The only time evaporation becomes an issue is if you run one peristaltic pump at a time. But if you run all 3 pumps simultaneously (concentrated brine, rodi and waste) then you won't disrupt the evaporation level.

As mentioned precipitation is your biggest concern. I've taken it to 70ppt without any visible signs of precipitation. I'd be curious what your experiment yields.

As for the DOS, I'm not 100% sure that would be the best option because of the way the software breaks up dosing with tdata. Ideally you want all pumps to run at the same time and I'm not familiar enough with DOS to know if that's possible.

I made my own arduino based awc that allows for easy programming based on what I mixed the concentrated salt to. I'm lazy and dump 2 bags of salt in roughly 55 gallons and whatever that mixes to (sometimes 60ppt, some thimes 65ppt) gets put into the awc. No more mixing to exact numbers haha.



No this communicates with my diy kalk controller, and that communicates with apex in a very basic way.

Although, you might want to check github because there are some great patches into fusion. Some that mimic modules and also read data. For me that's far beyond my scope of expertise.

You just do it all, huh brother!!?! For years i've been amazed with your reef tank. Recently delighted by your willingness to help a stranger(for nothing) with your 3d printing. Now i find out you do audrino too!! You've reached what I call "reef master supreme deluxe" status. I would love to learn audrino, getting tired using/wiring 8 relays to do what 2 can do with some logic and a few inputs.. where would you say is a good place to start learning for someone with no clue about audrino but a decent understanding of electricity?

 

[Sisterlimonpot]

You just do it all, huh brother!!?! For years i've been amazed with your reef tank. Recently delighted by your willingness to help a stranger(for nothing) with your 3d printing. Now i find out you do audrino too!! You've reached what I call "reef master supreme deluxe" status. I would love to learn audrino, getting tired using/wiring 8 relays to do what 2 can do with some logic and a few inputs.. where would you say is a good place to start learning for someone with no clue about audrino but a decent understanding of electricity?

Thank you. That actually means a lot. Every now and then, I'll get the urge to engage in meaningful conversation. Hehe

When it comes to the concentrated brine idea, I think there's some promising uses for the application. Although, I think it's still in its infancy and has a lot to be discovered, I think peristaltic pumps make it viable to explore.

I was so scared that my salinity would creep one direction or the other. But I've been doing this for over a year now and it's no different than what the skimmer does to salinity (throwing out a cup of skimmate each week to have it displaced with rodi). Not to mention, the jury is still out about the unknowns about what other trace elements are being precipitated from the concentrated salt mix and how that effects a reef long term.

As far as the arduino, I'm not a coder, I struggle with comprehension. my advice and what I did, is to befriend someone that knows a lot about software and coding, then be at their mercy. But his advice would be to get a starter kit and start with the blinking led tutorial and go from there. Haha

And perhaps @shoedy will bring his talents to this hobby.