Hi, I thought I?d share my outside tanks with you. I use them to experiment with but not experiments like cruel ones. Sometimes I?d put a plant in to see what happens to it outdoors, or see if coldwater fish do in fact breed outside. No heaters, pumps (except in the ponds), filters, lights anywhere. (Obviously no dosing either). I have in fact seen guppies, platies and swords breed in this pond right through winter. (400L) It?s been running for almost 2 years now. The comets are doing strange things in here (behaviourally) and I already have quite a few babies. (2000L) My cycling partner and I built this from brick and cement about 2 years ago. No filter, just a pump and UV light. The black thing above the waterfall is a temporary thing I constructed to filter dead algae from the UV light. Basically it?s just a bucket with folded shade cloth. Works well. I?ll remove it one day when it?s no longer required. If I find that time to be elusive, I?ll build a filter behind the wall. I call this my ?stoep tank?. It was pretty much a river biotope until I started putting polysperma and java ferns in too!! 5 Comet babies from the big pond are housed in here along with 3 platies from the smaller pond. This is el-Natural Walstad-style in it?s purest form. The filter is to clear up the water. Then I?ll remove it. Set up 3 weeks ago so it?s very much still a work in progress! ?I have a tank. Don?t know what to do with it?. Ah, I know!! Put moss in to see how fast it grows outside!? That?s what happened here. (20L) 2 platies provide nutrients. I don?t know what I?ll do here?. Maybe breed guppies?. I like their colour. (50L) Also Walstad style. This is my latest creation ? also completely el-Natural (90L). I only set this up the weekend, so it has no fish yet. Just snails. No idea what I?ll put in here yet. It is set up on Jeni?s kennel and yes, the thing on the left is a real rock. I picked it up in the Magaliesberge in 1988. And that?s it. I hope you enjoyed looking at my alternate tanks. Any constructive comments, ideas, tips, etc would be welcome. I have no particular direction with any of the above, so am willing to mix and match at random. The principles of fishkeeping still apply though!! Cheers!