What to do with your fish tank when you go on vacation

A compartment feeder is the right shape of tool for this job, because it separates the two decisions. You portion each compartment yourself, with the food your fish already eat, in the amount they already get. The device's only job is to turn the drum on schedule.

That is the opposite of a feeder block, which decides the portion for you as it softens and keeps deciding while you are not there.

Fourteen meals at two a day is a one-week trip, which is exactly the case this page is written for. Mount it on a hood, a condensation tray or the glass edge with the included brackets, and run it for a week before you leave so you can see what it actually drops.

The honest costs. Fourteen compartments is a hard ceiling: at two meals a day it is seven days, not a fortnight, and there is no way to extend it. The battery is not included on the US listing. It needs a gap to drop food through, which a tank with a close-fitting glass top does not have until you make one. And a dry compartment feeder in a humid room can cake flake food into a plug that does not fall — the reason the trial run matters.

The reason to spend this much is not the programming — it is the fan. The failure mode of every drum feeder is damp food caking inside it, and a tank is a humidifier running directly underneath the device.

A unit with active ventilation is addressing the actual cause of automatic-feeder failures rather than adding feed times nobody needs. The low-battery warning is the other quietly valuable part: a feeder that dies silently on day three of a two-week trip is worse than no feeder at all.

If you travel a few times a year, a feeder that lives on the tank permanently and gets refilled is a better arrangement than one you set up each time.

The honest costs. It is roughly three times the price of a compartment feeder that will cover a one-week trip perfectly well. The clip bracket is reported not to open wide enough for some rimmed tanks, so check your rim first. The battery type is not published. And 100 mL is a capacity figure, not a portion figure — what it drops per feed depends entirely on the setting you dial in, which is another argument for testing it.

This is the cheapest pick here and the one most likely to be the difference between coming home to a normal tank and coming home to a green one.

An unattended tank is lit by whatever you left switched on. Left off for a week, live plants stall and start shedding. Left on for a week, you have given algae a seven-day uninterrupted photoperiod with nobody doing water changes.

A timer holding 6 to 8 hours a day keeps the tank on its normal schedule, which is also what the fish are used to.

The honest costs. No electrical rating is printed here because we could not verify one from a source that responds to us, so check the listing against what you are plugging in. A digital timer loses its program in a long outage unless it has battery backup, which is exactly the scenario you are not there for. Put only the light on it — a filter or heater on a timer is a far worse problem than any algae.

NT Labs' advice on this is specific and worth following exactly: do a water change a few days before leaving rather than just before. The reason is that a water change is a disturbance, and you want to be present for the day or two afterwards in case something is off.

A tank with low nitrate and clean substrate when you walk out of the door has a much larger margin for a week of no maintenance than one you tidied up at 11pm the night before.

The honest costs. You carry the water, which is fine on a 10 or 20 gallon tank and the reason people stop doing changes on anything bigger. There is no flow control other than your thumb. And on a sand-bottomed tank the technique is different — hover rather than dig, which is covered on our sand page.

This is the pick that decides whether you should be reading the rest of this page at all.

A settled tank with zero ammonia, zero nitrite and a sensible nitrate reading will coast through a week unattended. A tank that is still cycling, or newly stocked, or reading ammonia for any reason, is a tank that needs daily attention — and leaving it for a week with a feeder dropping food into it is how people come home to losses.

Test a week out, not the day before. That leaves time to do something about a bad number.

The honest costs. It does not test hardness, chlorine or alkalinity. It is slower and fiddlier than strips, the nitrate test needs the second bottle shaken hard and then a wait, and the color card is genuinely hard to read between adjacent shades under warm light. Reagents expire, so an old kit deserves suspicion before an important reading.

The skip entry, and it is the product most people reach for first because it is the cheapest thing on the shelf.

The objection is not the formula. Practical Fishkeeping notes that the old plaster-of-Paris blocks could raise general hardness to unacceptable levels and that gel-carrier versions avoid that, so the modern products are better than their reputation on water chemistry.

The objection is control. A block releases food as it softens, at a rate set by your water and your fish's enthusiasm rather than by you, and whatever is not eaten becomes ammonia in a tank with nobody to test it. Practical Fishkeeping's own advice tells you something important by implication: run trial sessions with smaller pieces well before the holiday, because fish may not recognize a large unfamiliar object as food at all. A feeding method your fish might ignore is not a feeding method.

And for the trip most people buy it for — three or four days — the correct action according to the aquatics trade is to feed nothing at all.

The honest costs of the skip. It is very cheap, it needs no batteries and nothing can fail mechanically, which is a real argument in a tank with no feeding hole in the lid. Retailer listings for the Weekend and Vacation blocks disagree with each other on duration and we could not reach a Tetra document stating one, so if you do use it, read the package you bought rather than anything online.