FROZEN FOOD DELAY FEEDER

After reading a Facebook post on "Seahorse Source group", I have done a lot of experimenting with an Ice Delay Delivery System.
I started with conventional funnels but found the food adhered to the funnel when ice melted.
I progressed to experimenting with a canning funnel and eventually found a way for it to work.
For each individual tank, it is necessary to experiment to find the right combination of amount and diameter of ice in order to achieve the delay interval you wish.
My experiments were done using a freezer at -20 F, with the room temperature at 70 F. If the ice OR the room is warmer, obviously the time interval of delay is reduced.
As I had no REASONABLE way to cap a canning funnel to freeze the ice in it, I used various straight sided vessels to experiment with such as two sizes of plastic measuring cups that were I think initially from TIDE liquid detergent, but they only gave me up to 2 1/2 hours maximum.
I ended up going with just a standard 1 cup Pyrex glass measuring cup.
I also tried the food previously frozen in an ice cube tray and placed it on top of the ice delay pellet, but ended up doing a two stage freezing of the pellet with just under half the water and then adding the food and remainder of the water after the initial freeze which took several hours.
Also, my experiments were done using the canning funnel sitting on top of a clear plastic container so I could keep it with me wherever I was and thereby hear when the ice pellet dropped, indicating the end of the delay interval. Then I finalized it using it on one of my tanks.
I did have to have an elevated holder for the funnel when over the tank because the heat from the light fixture screwed up my timing.
I initially chose to get a three hour delay as that is what the Facebook poster was requiring. Once I got the timing zoned in, I did find variances of 23 minutes based over four separate trials, from 7 minutes under to 16 minutes over the 3 hours.
Knowing my trial parameters posted just above, one can probably get fairly close to their objective by estimating how much and what diameter of ice to start their own trials.

MY STARTING TOOLS

CANNING FUNNEL
ONE CUP PYREX MEASURING CUP
FROZEN FOOD
HOLDER FOR CANNING FUNNEL OVER TANK

PROCESS

I added a little under 2 ounces of RODI water to the measuring cup and placed in the freezer until frozen or almost all frozen.
Then I added the rinsed frozen food to the frozen surface layer and added the remainder of the water which now totals 4 ounces and placed back in the freezer.
When frozen completely I ran cold water over the OUTSIDE of the inverted measuring cup, gradually turning to hot water and running until I can release the ice pellet which I then place in the canning funnel, small diameter down.

MEASURING TIME TO DROP

Now put the canning funnel over a clear container to simulate the tank and wait for the "clunk" of the pellet dropping so I know just how long it takes for that size ice pellet.
After trials have established you have the time of delay you need, then you need to trial it over the tank as I found that ambient temps at the tank were higher, in my case due to the heat from the lighting fixture.
I solved it by raising the funnel higher so heat doesn't affect it, but, I could just as well have experimented again with larger ice pellet until I had what actually would work over the tank.
I used the centre section of a 2 litre pop bottle that I cut tabs that sat on the wire supports of my light and elevated the funnel.

Once the pellet drops, it took less than 5 minutes to disperse food and disappear.

Now, I figure I can go further, using more canning funnels and progressively large ice pellets timed to do more feedings later in the day, say four times at four hour intervals, allowing a full day's feeding so I can follow with a day without food and then be able to go away without having to have someone to feed them for a weekend.br Total volume of RODI water pellets would have to be no more than the amount of evaporation naturally occurring.