1 - Grasslin rondomatic 400 auto feeder: Ties with the rena below. It is easy to clean on an absolute level - I have disassembled 2 of these and cleaned the individual gears and levers etc. and this cleaning restored them to 100% functionality (powdered flake that I have been using can jam internal gears rarely but occasionally if you shake it upside down too much). Also - these are easy to repair if you already have a spare to cannibalize BUT if this one auto feeder is all you have you might have to buy one more of these for parts, this repairing only is practical if you have a couple or a few or many of these rondomatic 400s. Also - the tiniest spring in these can be replaced if needed by a carefully sized rubber band (I had to do this once as I accidentally extended this spring too far once, also - these tiny springs (only one tiny one in each rondomatic, the other spring is bigger and I think it can also be replaced with a rubber band if needed too (carefully sized) can be easily lost) but of course I am sure the manufacturer (grasslin) doesn’t endorse the rubber band - part of this repair. I would love to see bigger rondomatics. Strangely enough in the distant past the rondomatic 800 was their flagship auto feeder product and it even had a heater that heated the food trays - the rondomatic 400 is the same as the rondomatic 800 except the rondomatic 400 is much smaller and has no tray heating. Bigger rondomatics and added heat is on my wish list. You can use rondomatic 400s for big setups but you have to spend much more money because you might have to buy many more rondomatic 400s to add up to the 800’s capacity. This auto feeder ties in my opinion with the rena auto feeder I reviewed and write about below.

2 - Rena auto feeder: The rena ties with the rondomatic 400 I wrote about above in my opinion. It heats the food drum, has adjustable output (i.e. more or less food) works in all lighting conditions or selectively only during lights on time (i.e. during the day only for example), has one of the largest food drums for aquariums for consumers and includes a built in mixing bar, and the food drum is heated to prevent clogging. You can feed a variety of foods with this auto feeder but not liquids whereas the rondomatic 400 will feed liquids excluding evaporation in comparison. This rena auto feeder has a bright led light display in back that clearly tells you how many hours it will wait between feedings every day and the number of full rotations of the food drum it turns when actually feeding, up to 3 times per feeding and it can feed every 3 hours to a much less frequency. The drum is removable (don’t turn the drum while removing or any other time - it might break the auto feeder) and of course refillable. I find only 2 flaws with this rena auto feeder - you can’t feed liquids with it and as a result of power outages (no batteries can be used except I might be able to make a non-rechargeable battery backup for it with any battery type - but I am a competent electrics hobbyist and hobbyist electrician, or any one with enough money can just use a computer ups (a very light duty one can be used as this rena auto feeder only uses about 3 watts according to a label I see printed on this rena auto feeder) or other compatible or suitable battery backup) when the power comes back on after a power outage the frequency per day setting and the number of rotations per feeding setting resets to 2 feedings a day and 1 rotation of the food drum during each feeding, and this lack of battery backup is a significant lacking but at least this rena auto feeder is always on excluding power outages, by the ac power it uses (wall power). Otherwise an excellent auto feeder in my opinion.

Summary of 1 And 2 - rondomatic shortcomings = small, not heated. Rena shortcomings = no battery backup, no ability to feed liquids. Both are excellent auto feeders compared to the rest of the market. Both the rondomatic 400 and rena auto feeders are expensive though (commonly around $70.00 each). I have tried cheap auto feeders before - the Penn Plax daily double works good until about 1 or 2 years later when for some reason they stop turning, it is a clockwork device like the rondomatic 400 (clockwork design) but of a lower quality making them fail far more often than the rondomatic 400s. The nutramatic 2xs are good but have small food drums and barely any if any mixing bar. Cheap fish feeder blocks are notorious for killing the fish they feed and make a mess while the owner is on vacation or otherwise gone, also - these more expensive auto feeders compared to the feeding blocks last a lot longer therefore feeding regularly a lot longer than those weekend auto feeding blocks. As far as the consumer market of auto feeders goes in the case of a large fish or more I would recommend checking out a pond auto feeder (such as large cichlid tanks) as they are approximately the same price as these aquarium ones but have a way larger reserve and feed a lot more per feeding. Some of the above I have already mentioned here but I thought I would consolidate it. I currently use rondomatic 400’s, a rena, and 2 nutramatic 2xs and I am very happy with them after I started auto feeding all of the time and after my Penn Plax daily double petered out. Around the time I was using the Penn Plax daily double, I was also using a rainbow lifeguard auto feeder that needed vibration to work reliably (like the rondomatic 400s, but not the rena or the nutramatic 2xs I think), and the rainbow lifeguard auto feeder got stuck with a piece of airline tubing in it’s output opening and I couldn’t un-jam it and that led to a mess of various types of oils I injected into it from outside it’s body or chassis and I never did manage to un-jam it so it’s retired now, but with vibration such as a cheap air pump rubber banded or bungeed to it’s food drum makes it practically 100% reliable minus the potential for permanent jamming. All of the above drum auto feeders (except for the Penn Plax daily double I have, and the rainbow lifeguard) are computerized. I am pretty sure the nutramatic 2xs are computerized and the rena is definitely a computerized auto feeder. I thought this little article I wrote here might help some people given it’s vacation time for most people, especially this time of year (middle summer).

Good luck all and later!