Just a brief update for now:

I've had my continuous water change running for the past 3 weeks or so. I'm really happy with how stable it's been. If your interested, I documented it in post 20 of this thread. If you saw my original plans, you will be pleased to know that in the end I scraped the whole loop thing and just went with a basic setup. There are a few tricks to getting it balanced though.

I've ordered a Probe Expansion Module and a Salinity probe for my Apex to monitor salinity in the tank. I have no plans to use this for control - just monitoring and alerting. I haven't had good luck with these probes in the past, but I will try one more time. Hopefully it works out better this time.

I've added two MP60s to the tank. Wow these are awesome pumps. I haven't played with all of the different modes yet. I also have the Apex WXM on order.

I've been playing a lot with the flow in the tank recently. It's not easy to get it perfect. It seems that the powerheads either kick up sand or cause problems with surface skimming. I think I have everything figured out.

I still don't have any real lights on the tank. I'm told that I should have some really nice LEDs within the next week or two. Patience is a virtue.

Things have generally been stable. I'm still trying to figure out the best way to seed the dry rock in the tank. I do have some ideas but nothing confirmed yet.

Also if your interested - I posted some pictures of my 90G tank here:

http://www.canreef.com/vbulletin/sho...threadid=73619

I don't really plan to do much more with this tank. I'll probably take a few more pictures before it gets shut down. I just thought it would be fun to share how it looks now.

- Brad

(Flow should get better over time as the sand starts to get a biological film over the grains.)

Wow that is quite the writeup for water changes. :) Neat ideas!

I suppose an alternative to flow meters on the peristaltic pumps you could install high and low level sensors in the sump? If one of the pumps failed, blocked or otherwise became out of calibration it probably wouldn't take long for the sump level to rise or fall so a few float sensors in there might be a simple approach ?

Thanks Tony!

The challenge with level sensors is evaporation and ATO. It would work if the pump taking water from the tank failed. I think the rate of water change would exceed evaporation and the water level in the tank would slowly rise. However, if the pump adding new water to the tank failed, the ATO would keep the water level constant.

My current plan is to observe the system using a salinity probe. If either pump fails, the salinity should drift. If the calibration of the pumps is not perfect, the salinity should drift. I have no plans to use the salinity probe for control, but it should provide a good indication of the CWC operation. I may use it to automatically shut the whole system off if something doesn't look right, but the rate of change should be small enough that I can manually react long before a real problem arises.

My only concern with the Salinity probe is getting a stable reading. When I tried this on my 90G tank, I was never successful in getting an accurate and stable reading. If the probe drifts on it's own, it won't tell me anything about the operation of the CWC. The initial calibration doesn't have to be exact, but the measurement will need to be 100% stable. I'm hoping that I can find a way to achieve this with the newer hardware and a better understanding of how the probe works. We shall see soon enough :smile:

The system is working well for me now, but there's probably some minor improvements still to be made.

March FTS

http://owa.footit.ca/wwwimages/fts/f...2011-small.jpg

• I have a light! - Vertex Illumina 260 - SR 1800.
• I've had 4 independant 15A circuits run to the control room behind my tank. Each of these circuits is protected by a GFCI outlet. Critical equipment is split across independant circuits so that if a GFCI outlet trips it will not cause a tank crash.
• I have the salinity probe working. It's certainally more stable than the one I had with my AC3, but still tends to wander. The error margin seems to be about +/- 0.3 ppt. That's probably good enough for an early warning system on my CWC.
• I have the Apex controlling the VorTech pumps. I really dislike programming the VorTech's using the EcoSmart Controller colour system. For such advanced pumps you would think they could include a simple LCD display and menu? - Anyway, I created a set of virtual outlets on the Apex which map to VorTech pump profiles. I can switch between pump profiles by activating the virtual switches. This works great for testing the various modes. Default control moves through various profiles based on time-of-day.
• I've been working on getting my autofeeders working. You can see them in the FTS above. More on this later.
• I've started building the panneling for the stand. This has proven to be a long and drawn out process as I can't seem to find the motivation to complete this project. At least it's in progress.
• I've replumbed my bio-pellet reactors. I had the two reactors in series but found the pump to be way to powerful. They are now in parallel and I've added a tee for the carbon and phosphate reactors (not online yet). I am much happier with the new configuration.
• I've started setting up the Vertex RX6-Duo Calcium Reactor.

The tank has been stable!

Looks gerate...Any detail pics of the mounting apparatus?

Looks sweet.

Hey Cale

Thanks for the props. The light is currently suspended from a light rack that was built as a feature of the stand. I have to admit that this has been very useful, but ultimately I don't think it will be my final solution. One problem is the rails are positioned at the outer edge of the tank whereas the mount point for the Vertex is about 10 inches inside. What this light rack does is buy me time while I figure out how to suspend the light from the ceiling.

http://owa.footit.ca/wwwimages/light...lightrack1.jpg . http://owa.footit.ca/wwwimages/light...lightrack3.jpg

I wanted the ability to slide the light out of the way, so I hung the lights from a short section of acrylic tubing. I used a couple of felt guard sticky things that protect floors from furniture to allow it to slide. Again, not perfect, but it serves the purpose.

Thanks Greenmaster. Can't wait to see your tank take off. You've really shown your ability to be patient these last couple of months. Good job!

I will be very interested to see what you think of the lighting , and how it works out for you . I was looking at these as a possible option one day for me as well.

Everything looks well done so far . Great job.

That's a clever way to slide your light! I think I just sorted out how I'm going to allow my pendants to individually slide within my canopy thank-you =)