New Swiss 1900 liter (500G) Build

[revhtree]

And finally, a video (I'm still not good at these but...):

Beautiful system!

 

[Laith]

Beautiful system!

Thanks! Still a work in progress...

 

[panic]

What a great build!!

 

[Laith]

What a great build!!

Thanks. It has been fun (most of the time!). ;Joyful

 

[MrStoffel]

I send off two water samples every three months for ICP testing, one from the tank and one from my RO/DI top up tank.

One thing that kept niggling at me was that the ICP test of the tank water constantly came back with a salinity of 38ppt. I'm pretty sure this is due to evaporation of the sample by the time they test the salinity of it. My Hanna digital refractometer usually shows 1.026 - 1.027 and when I test it with RO/DI water it shows 1.000.

But just to have the best reference possible, I purchased this which arrived a week or so ago:

From Fauna Marin. The graduated cylinder makes it easy to measure. The only downside is the hydrometer is calibrated at 25C so you need to adjust the result up or down by 0.00035 for every 1C your test sample varies from 25C (up for temps above 25C and down for temps below 25C).

When I tested my tank water, my Hanna was showing 1.027. The Fauna Marin hydrometer after temp adjustment gave me 1.0273. Close enough.

A bit on the high side but nothing to worry about: I've adjusted my AWC to take out more water than it is replenishing with fresh saltwater, 16.5l a day out and 10l a day in. This will slowly bring it down.

At least I know that the Hanna is more or less showing correct numbers. I'll use the hydrometer from time to time to double check.

38ppt by the way is 1.0286 at 25C...

Did you take into account the hydrometer you are using is measuring density and not specific gravity?
I have the same one and was using it wrong for 3 months. I discovered the same throug icp testing (also high salinity).
Some information about the differences:

https://www.tropic-marin.com/wp-content/uploads/2013/12/tips-tricks_difference-between-density-specific-gravity_gb1.pdf

 

[Laith]

Did you take into account the hydrometer you are using is measuring density and not specific gravity?
I have the same one and was using it wrong for 3 months. I discovered the same throug icp testing (also high salinity).
Some information about the differences:

https://www.tropic-marin.com/wp-content/uploads/2013/12/tips-tricks_difference-between-density-specific-gravity_gb1.pdf

Thanks for that interesting info (by the way the hydrometer I have is from Tropic Marin and not Fauna Marin, my mistake).

But I'm having a bit of trouble understanding what exactly the document is saying you should be doing in order to correctly measure using either one or the other versions?

Could you clarify please?

 

[MrStoffel]

Thanks for that interesting info (by the way the hydrometer I have is from Tropic Marin and not Fauna Marin, my mistake).

But I'm having a bit of trouble understanding what exactly the document is saying you should be doing in order to correctly measure using either one or the other versions?

Could you clarify please?

Based on your images, your hydrometer is measuring density (dichte in german) and not specific gravity. I have the exact same model. In the US there are models sold with a different scale, reading specific gravity.

So if you measured 1.0273g/cm³ on the hydrometer scale, that would be around 1.0303 sg or about 40ppt

The same thing happened to me a few months ago, my refractometer was way of and i could not even calibrate it correctly anymore, so i tossed it. Now i only use the TM hydrometer and my icp always confirmed my readings so far.
I read around 1.0235 g/cm³

I use this website to convert my hydrometer measurement to salinity:

Salinity calculator

A unit converter for calculating salinity in marine aquariums. The calculator supports conductivity (mS/cm), salinity (PSU og ppt), density (g/cm³) og specific gravity.

reefapp.net

 

[reefpizza]

Awesome build! Keep going! I also have similar hydrometer very accurate!

 

[Laith]

Based on your images, your hydrometer is measuring density (dichte in german) and not specific gravity. I have the exact same model. In the US there are models sold with a different scale, reading specific gravity.

So if you measured 1.0273g/cm³ on the hydrometer scale, that would be around 1.0303 sg or about 40ppt

The same thing happened to me a few months ago, my refractometer was way of and i could not even calibrate it correctly anymore, so i tossed it. Now i only use the TM hydrometer and my icp always confirmed my readings so far.
I read around 1.0235 g/cm³

I use this website to convert my hydrometer measurement to salinity:

Salinity calculator

A unit converter for calculating salinity in marine aquariums. The calculator supports conductivity (mS/cm), salinity (PSU og ppt), density (g/cm³) og specific gravity.

reefapp.net

Well that's an eye opener! For some reason I always assumed that specific gravity and density were the same...

My Hanna Seawater refractometer (HI-96822) which I just used shows 1.026 sg, 35ppt and 34 psu. Could it be that far off?

It would explain the high ICP salinity numbers...

I'm going to measure again just now with the hydrometer and see what it says. According to the calculator you linked to, the hydrometer should show 1.0224 at 27C.

I'll post the results.

MrStoffel, many thanks for pointing this out to me. I would never have caught on. Appreciated! ;Happy

 

[Laith]

The hydrometer shows a reading of 24.9 which is a density of 1.0249. The water temp is 27C.

When I plug 27C and 1.0249 density in the calculator, it shows:

PSU/PPT of 37.9
SG of 1.0285

Interestingly, the ppt almost matches the ICP result of 38...

Time to change the AWC setting to take more water out than fresh saltwater going in to slowly bring down the salinity.

I was using the Hanna as well to measure my fresh saltwater. The fresh saltwater tank will need refilling in the next couple of days so I'll use the hydrometer when I make the new mix.

I still can't believe that the Hanna could be so far off! :mad:

 

[MrStoffel]

Good thing you know the issue now, i will never trust anything other than a hydrometer from now on!

 

[Laith]

I think I'll continue to use the Hanna, but now I'll be looking for a 32ppt on it to tell me that I'm actually at 35ppt. It's just easier and quicker to use the Hanna (a bit of tank water in the measuring area, push a button and instant reading) but I now know the correct offset to make to the numbers it gives.

What I'll do is compare the hydrometer to the Hanna once a month to make sure that I'm still using the right offset.

 

[reefpizza]

The hydrometer shows a reading of 24.9 which is a density of 1.0249. The water temp is 27C.

When I plug 27C and 1.0249 density in the calculator, it shows:

PSU/PPT of 37.9
SG of 1.0285

Interestingly, the ppt almost matches the ICP result of 38...

Time to change the AWC setting to take more water out than fresh saltwater going in to slowly bring down the salinity.

I was using the Hanna as well to measure my fresh saltwater. The fresh saltwater tank will need refilling in the next couple of days so I'll use the hydrometer when I make the new mix.

I still can't believe that the Hanna could be so far off! :mad:

I have done the same discovery a year ago, my tank crashed for the hanna readings...

 

[Laith]

I also need to spend some time and learn how to really use the power of the Profilux.

For example, at the moment when the low level float switch in the fresh saltwater reservoir is triggered, the litermeter AWC is turned off and the solenoid is powered on to start filling the reservoir with RO/DI water. However I'm currently having to manually switch off the litermeter before the reservoir is filled otherwise it will be turned back on when the high level float is triggered and before I've mixed in the salt...

There must be a way to keep the litermeter off until I tell it to power on once the fresh saltwater is mixed.

;Bookworm ;Bookworm ;Bookworm

Just for info, I've sort of changed how this works. When the low level float switch is triggered, the litermeter AWC is still turned off and solenoid is still powered on to start filling the reservoir.

But now instead of waiting for the reservoir to fill (about 12-13 hours) before mixing in the salt I add the salt any time after the water level is high enough for the mixing pump to be switched on. I leave the mixing pump on for the rest of the fill and the salt is thoroughly mixed in by the time the high level float is triggered to stop the fill. At this point the litermeter AWC comes back on automatically, triggered by the high level float.

It is usually not a problem to make sure I add the salt before the high level float is triggered since I have about 12 hours to do so...

Much more convenient doing it this way.

 

[Laith]

Wow, time flies! Been very busy so difficult to find time to update.

Tank and inhabitants doing very well...

Speaking of inhabitants, I mentioned a while back that I got a harlequin shrimp to help control my asterina starfish population and that I hadn't seen him for ten days.

Well, about a month ago (so a couple of months after putting him in the tank) he appears, fat and happy. He's made his home under the green montipora and does come out from time to time.

My asterina starfish population is now under control and it looks like he gets a constant supply of them as I constantly see 20 or so of them in the DT. I assume they are multiplying in the sump so the sump has become the harlequin's auto feeder!

My son has named him Harley.

More updates to come soon (hopefully)!

 

[Laith]

My trial with the Kalkwasser dosing...

Background if you haven't seen the post(s): I decided to try to dose Kalkwasser to the tank for two reasons:

- Raise the pH of the tank (which was between 7.8 and 8.1)
- Reduce the amount of carbonate and Ca Balling method volumes that I was dosing. This because the time period between refilling the carbonate and Ca containers was getting shorter and shorter given the daily amounts required to keep up with the tank consumption (720ml of carbonate and 168ml of Ca per day).

So I set up a separate Kalkwasser dosing setup using one of the GHL Doser pumps to add 10l of Kalkwasser per day, below the average evaporation rate of my tank so that this wouldn't mess up the ATO.

For two days this worked ok, raising the pH to between 7.9 and 8.2 but then the pH swings went back to as before. I thought that I need to add more Kalkwasser powder to the container as the initial amount I added was 25g which with later calculation would only provide enough saturated Kalkwasser for about two days. So I upped the amount to 125g: pH went back up slightly but then dropped again.

I stopped the Kalkwasser experiment at this point to try to figure out what was going on... and I was going to be away during the summer for a couple of one week holidays and didn't want to leave the experiment unintended.

More to come...

 

[dragon99]

What are you using as the the kalkwasser reservoir and how big is it? You mentioned starting with 25g of powder and then going to 125g. Depending on the size of the container you might not be reaching saturation. This calculator is helpful for checking https://www.hamzasreef.com/Contents/Calculators/KalkContribution.php

I dose kalk as my only alk/ca supplement currently (~4.5L/day) and I still have swings, but my overall pH is about .2 units higher. Dosing the kalkwasser only overnight might be a good solution for you if the goal is to minimize the swing.

 

[Laith]

What are you using as the the kalkwasser reservoir and how big is it? You mentioned starting with 25g of powder and then going to 125g. Depending on the size of the container you might not be reaching saturation. This calculator is helpful for checking https://www.hamzasreef.com/Contents/Calculators/KalkContribution.php

I dose kalk as my only alk/ca supplement currently (~4.5L/day) and I still have swings, but my overall pH is about .2 units higher. Dosing the kalkwasser only overnight might be a good solution for you if the goal is to minimize the swing.

You can see the what I was using for the kalkwasser addition in this post:

Monster Build - New Swiss 1900 liter (500G) Build

The Macro Algae reactor is slowly starting to do its thing. Nitrates are slowly coming down and the rate of increase in PO4 is decreasing. If the trend continues, then it confirms something that I have been suspecting since I installed the reactor: it takes time for the chaeto to grow to...

www.reef2reef.com

It's the Tunze Kalkwasser "reactor" that I had laying around from when I used to only dose Kalkwasser to my previous tank. When the doser came on, it pulled water from the top of this container which pulled water from my RO/DI ATO tank into the bottom. The concept is that the fresh RO/DI water coming in at the bottom mixes with the Kalkwasser powder providing continuous saturation... I calculated that 125g should provide about seven days of saturation before needing to add more.

Thanks for that link, great calculator. Not sure how it applies to the Tunze reactor but it matches my manual calculation about how much to reduce dosing of the Balling carbonate and Ca amounts!

 

[Laith]

I guessed that the reason for the inconsistent results adding Kalkwasser that was was that I was using a free dosing pump on the GHL Doser 2.1. This doser does not provide enough flow through the bottom of the reactor to give optimal saturation. Even on it's high speed setting the dosing pump basically still does a fast drip.

So I've reinstalled the whole thing, still using the Tunze reactor but this time connected to my primary ATO pump (Tunze Osmolator). As before, I added 125g of Kalkwasser powder to the reactor.

After some calculation I reduced the Balling carbonate and Ca dosing by about 40-50% as this seemed to correspond with what the Kalkwasser would be adding given my average evaporation rate in the tank. I have the KH Director so that can compensate one way or the other regarding KH levels and for the moment will manually check Ca levels and adjust accordingly (when the ION Director is delivered I'll have that manage the Ca dosing as well!).

I installed this setup on the 20th of September and the results are much better than when using the doser: here you can see the pH readings since the 18th of September:

Basically I'm now getting between pH readings of between 8.0 and 8.3-8.4 during a 24 hour cycle.

The readings are not that accurate: I moved Kalkwasser topup is now added into the overflow box of the tank (just to make very sure that no siphon can happen from the reactor into the tank!). Water then feeds into my Rollermat but the water exit from the Rollermat is where my pH meter is currently located so every time the ATO comes on I see a rise in the pH reading of about 0.2 before it comes back down to what it was before. The readings are recorded by the Profilux every hour so you can see some erratic swings in the graph depending on whether the recorded reading occurred at the same time as the ATO was on... . But the trend is obvious...

I'll move the pH meter further down the sump so that the water it's reading has had more of a chance to mix well.

 

[Laith]

Here is a picture of the reactor when I had it running with the doser. It's now in the same location but water is pumped into it from the ATO RO/DI reservoir (which it is sitting on) and the output goes up to the overflow box. I've put a one way valve on the tube going from the pump into the reactor to avoid the Kalkwasser draining down into the RO/DI reservoir...