High Tide Aquatics

Got my fresh food autofeeder working today!

Scott Sweet

Supporting Member
I have my return water line going through a small refrigerator with a injector. Each food is fed 2x per day, 5ml each. :)


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Pretty cool. How’s it work exactly with the injector? What kind of dosing pump is that, and are you concerned about it handling the low temperature? What temp is it at in the fridge?
 
Pretty cool. How’s it work exactly with the injector? What kind of dosing pump is that, and are you concerned about it handling the low temperature? What temp is it at in the fridge?
The venturi injector is similar to ones used with skimmers or ozone (Venturi Link). The water flows through the main part. The nipple naturally sucks air, but in my case...the food. The dosing pump is a GHL pump. The refrigerator is a 1.7 cu. ft Danby (Refrigerator). It has to be one with a compressor...and no freezer. I drilled a hole on each side. I can get the fridge down cold enough.
 
I got one of those set up too. I can't figure out how to post .MOV files so only have screenshots to show. I just mounted mine over my sump and drilled a hole in the bottom to dose directly into the return section of my sump. This one is technically an electric cooler too, so it only gets down to 40-45 degrees, but hasn't been a problem for the Oyster Feast that I dose.
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Cool, I need something to dose PE calanus (P.U. calanus) so I don’t have to handle it anymore. Also need the hood raiser :)
 
I'm curious, why the decision to run a line with tank water through it, as opposed to keeping the doser on the outside and have the smaller holes just for the dosing lines in the tank. I would think running tank water continuously though the fridge would do 2 things, 1) cool the tank ever so slightly, and 2) make the fridge work harder to keep cool. Plus I might worry about potential condensation issues on the dosing pump's electronics, then again never put a computer inside a refrigerator so don't know what would happen :D While outside the tank, there might be a bit of food in the small amount of tubing outside the fridge but that shouldn't pose much of any problem assuming you're dosing some what regularly and not once a week or something.
 
I'm curious, why the decision to run a line with tank water through it, as opposed to keeping the doser on the outside and have the smaller holes just for the dosing lines in the tank. I would think running tank water continuously though the fridge would do 2 things, 1) cool the tank ever so slightly, and 2) make the fridge work harder to keep cool. Plus I might worry about potential condensation issues on the dosing pump's electronics, then again never put a computer inside a refrigerator so don't know what would happen :D While outside the tank, there might be a bit of food in the small amount of tubing outside the fridge but that shouldn't pose much of any problem assuming you're dosing some what regularly and not once a week or something.

You bring up some good questions Mike...I thought about that :). I am using Reef Nutrition food which needs to stay refrigerated or it will spoil. Ambient temperature outside the refrigerator is quite warm because it is near my 5 light power supplies and in a closed cabinet. You will need to see the full setup to see what I mean. The time the food would remain in a warmer climate would definitely affect the freshness of the food because it would be outside for over 24-36 hours with a lot of surface area (silicon tubing) that is warm. Keep in mind, I am only dosing 5 ml, 2x/day...the length of the tubing is more than 5ml which means you are not actually dosing the full length of the tubing at any one feeding.

Second, drilling 4 large holes (or 8 small holes) on the top was not something I really wanted to do. The amount of water going through the refrigerator is nominal...about 1 gal per minute...so cooling is really a non-issue and probably not going to happen because the amount of contact of the water to the cold is very short and PVC is not a good conductor of cold...though I wish it would because my tank runs warm. As for the electronics, cold won't really make a difference...but moisture could. This is one reason I do not have a freezer so it doesn't get real cold and freeze any moisture that might form. These smaller refrigerators with a compressor (not thermoheat transfer types) are pretty good at removing moisture as long as I don't have an open liquid container in the refrigerator. I am accepting the risk of moisture affecting the electronics though.

As for the fridge working hard, it really doesn't. The electric cord of the dosing pump is coming out of the door and isn't making much of a difference from my experience so far. It is plastic and the seal is just forming around the cord. The fridge is barely on now.
 
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Now you need a small gentle shaker table in the fridge, to keep the bottles nicely stirred.
Actually, that is why I use Reef Nutrition food...the stirring isn't really necessary...the critters stay fully suspended. I talked with Reef Nutrition about this up front. For some other brands, the food settles to the bottom and then you would need a stirrer for sure.
 
Note that a small part of the tubing right at the injector still stays warm in the fridge.
The flowing tank water will keep it warm.

For those that want the main line outside, an idea:
You can TEE in your RODI, inside the fridge. So any food in the line outside the fridge will get flushed out by RO water.
 
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