Mixing valve

[fishguy306]

None yet, still a work in progress. We got in three 300 gal storage tanks yesterday and will be plumbing them up soon.

That said, I did learn recently that the Apex is able to measure TDS with the salinity probe. So I'm thinking I can use a salinity probe and pH probe to monitor our stored water. TDS/pH is too low can set it to open a valve and add either tap or a buffer of some sort.

 

[Lepisosteus]

None yet, still a work in progress. We got in three 300 gal storage tanks yesterday and will be plumbing them up soon.

That said, I did learn recently that the Apex is able to measure TDS with the salinity probe. So I'm thinking I can use a salinity probe and pH probe to monitor our stored water. TDS/pH is too low can set it to open a valve and add either tap or a buffer of some sort.

Heads up with the apex salinity probes. I would not rely on them for continuously accurate measurements. They have lots of issues if you read up on them. I would always base their values off a secondary source.

Both the pH and salinity probe require adjustment time so any changes will not be noticed immediately. This will result in a huge delay between the pump shut off and the measured values in the tank. There have been reefers who have used the salinity probe for their ATO system...by the time the probe reads the change in salinity the actual value will have far surpassed what you want.

I would go with the drip meter suggested. You can rough test it first using a pair of 5 gallon bucket. I’m sure you could become accurate to within a few ml doing so. Just keep fine tuning the outputs.

 

[fishguy306]

All tanks will have their own pH probe in them, so we should see any issues with stored water pretty quickly. As for the probes being slow to react to pH/TDS changes, it is something I discovered when dosing a buffer in the past for a RO drip. Way I found around it was have the dosing pump run for 15 seconds, then off for 5 mins. In that time circulation pump runs mixing the water. If it is still not right dosing pump can run again after the 5 mins. Still wouldn't be perfect but it would give a good amount of time for it to adjust as needed.

I'm just not crazy about the drip meter. TDS of the tap water can change throughout the year and just gives overall less control of what is going into the water. Further it'll be harder to balance water production. If one day we use 700 gal then the next day we only use 100 you have to be able to adjust the tap water drip to keep it consistent. That just isn't something we want to have to worry about.