Hi, just wondering if feeding blocks are any good? I'm going on holiday for 2 weeks and we found these 2 week feeders that sit on the bottom of your tank. Do they work or am I likely to find an distressed (or worse ) fish when I get back?

They contain large amounts of ash which just pollute the water. If the fish are healthy then they will be ok for two weeks. Feed heavily until 3 days before you go and then lessen the feeding. 24 hours before you go do a huge water change and dont feed them. Add some live plants such as elodea for them to graze on and they will be fine.
Dont you have a neighbour that can come in a couple of times a week and you can leave a portion of food in some foil for each feed?
A good idea is a timer for your lights, just to come on for maybe 4 hours each day. Food timers are a good idea as well, but only if you were going for a week.

initially i would say no and tell you to run a million miles away from the things - i lost a little blackmoor due to the polluted water i had as a reuslt of a holiday feeding block.
Hoever, i have seen a few new varieties around, and have seen one being used (my boyfriend's family went on holiday and we saw the block working in their fish tank)
This kind was a white pyramid containing pellets and a spirulina algae block. I saw it in the tank on a couple of occassions and it seemed to work quite nicely, slowly dissoving and releasing pellets which the fish ate. It didnt seem to make much mess, and the goldies enjoyed nibbling at it.

My boyfriends family are still on holiday, and i am back in my house so we do not know if the fish are still alive and if the block was successful. But it looked quite good, and i will let everybody know if the fish survive and the water is still good.

SO at the mo i am at about 75% no way, and 25% maybe, on the topic of holiday blocks. They have a very bad reputation, and are a poor substitute for having a friend or neighbout pop round every now and again while ur away and feeding them a measured amount of food.

I think it might be a good idea to try one out before you go away. This is what i am planning to do before i go on another holiday. I think it makes sense to put one in the tank a few weeks before you go away, and observe what happens. That way you can see how much food it dispenses, how much mess it makes, whether the fish are getting enough food each...etc etc. This way if it does go horribly wrong you can do a big waterchange and correct any damage before it's too late. And if it does all go well, you can use one for the time you're away and feel a little happier that you know what will be going on in your tank.

hope that helped!! (my fingers ache now!!!)

ps- i have found that it is a good idea to buy a few cheap (small leaved - easier to eat!!) plants for the tank for when you are away. that way you know that the fish will not starve as there is natural food in the tank, and that they will be eating something thats actually good for them.

Fish can survive a long time without food. and they will usually munch on plants and algae in the tank all day anyway!!