Robert Smith

Stella, pH 8.8 would not be good for Al. That's pretty high, what's the special fish? Also, if you use tank salts, they could be a problem. SS is a very poor thermal conductor Since this is going to be in the water, why would you even need a heat exchanger? The water in direct contact with the peltier surface would do the job nicely (especially if there is flow). I assume that your filter is internal? I live in Oz and have a similar problem. We survived this summer, but things got a bit warm last summer. I have an external cannister filter (400L/m) for an 80L tank (vroom, vroom) and was going to try connecting a peltier cooler straight to the glass (on the outside). It's horribly inefficient, but it's only to take the edge off on those really hot days. Then I thought about buying one of those peltier car coolers and dropping the output tube from the filter through a heat exchanger in the 'fridge'.

Instead of LEDs why don't you try 12V cold cathode fluorescents (CCFL)? They come in a range of colours. Their output is low (a few watts) but for moonlighting it could do the job. I tied a UV CCFL but the output was too low, even for my 80L tank. You could even use low wattage (5W) 12V tungsten halides. If you use ones with reflectors you can direct the light. I use 'naked' (no reflector, just bulb) 12V "ultra white" halogen (40W total) to light the tank. Simple easy to install and only 12V for those who get nervous hanging 240V over a tank of water! My plants grow ok, but I don't have anything fancy (Swords, Val & something else which I don't know what it is). They occupy very little space (I have about 25mm headspace). I'm also playing with some bi-pin 12V compact fluoro's (direct replacement for halogens) to up the colour temperature of the light, but they haven't proven very reliable.

I think I've got the same snails as Alan. They look like Ramshorns but walk sideways. The biggest I've found were about 7-8mm diameter. They haven't got too bad, but they do eat plants. My swords are getting a little tattered in some places. I tried killing the snails off with CuSO4, but this didn't work very well and can be harmful on the tank if you keep at it or use a strong dose (also, if you have lots of snails and they all die at one it can mess with your tank too). I laid a snail trap which works (especially on the big ones). It's a small wide-mouthed glass vial (20 x 100mm) with a bit of nylon tied around the neck. I drop in a bit of cucumber and drop it into the tank so that it's on it's side. The snails go in during the night and you just fish it out using the nylon and keep going. However, my rummy nose tetras figured out that it was safe to go inside and now they eat the cucumber. I need a smaller mouthed vial.

Zev and Linda have found the answer! Osmocote "prills" Thank God for that. I can now relax and not worry about some giant nasty beastie emerging and devouring my fish. Although he'd probably have a fight on his hands with my psycho black phantom tetra. I'd never thought it would be possible to describe a fish as "rabid", but this guy qualifies.

Hi All, I have been doing some housekeeping in my tank (pulling plants) and noticed some very round stones that float! I've never seen them before, I assume they were buried in the roots of a plant. They are about 3 to 5mm in diameter, pale brown/tan (kind of stone coloured). they don't quite float, but strong currents move them around easily. They're tough, I have to exert quite a bit of pressure to crush them. I have tetra's and had guppies until the pretty but useless buggers kept dying. I've also recently picked up an infestation of Ramshorn snails from some new plants. Any ideas what they could be? I assume they are nothing to do with my (male) fish or ramshorn snails, and since no new beastie has suddenly appeared I assume they are either dead or very hibernated. Bob

From what I've seen, 3500K might be a bit on the cool side, but 5000K sounds about right for tropicals. Shallow water species of plant and fish are used to light which is more like natural sunlight (5500K), rather than deeper water fish which is more blue. I didn't have any problems with algae until the sun got low enough (winter is upon us!) to reflect off a neighbour's window and cuts across part of the tank. At that spot I have algae. When summer was in full swing my apartment got up to 35oC (I'm in Oz) and the tank started to overheat. The lamps wouldn't have helped, but they don't pump out too much heat and it's hardly noticeable). I'll measure the air temperature above the glass cover with a thermometer. The big advantage is that it's very cheap, very easy, very safe (any idiot can wire up 12V) and very small (I had only 25mm clearance between my hood and the glass cover). It's also quite artistic with the ability to create spotlight effects.

Pies, You've recommended 6000-7200K bulbs. What happens if you use others? You only really need lights for the plants. Of course, lighting can also make the tank look pretty. What's required for the plants? I'm using special 'ultra-white' 12V tungsten halogen bare bulbs (nominally 3500K for the bare bulb, but I've seen the sealed dichroic reflector versions advertised at 5000K) and my plants seem to growing ok. Since I've never seen anyone using these before (see my post under DIY light hoods) I was wondering about possible negative effects. Can anyone cast any light on this?

I'm a newbie to aquariums and while in the process of building my own 80L tank I got a rude shock when I found out what the lights cost for a sealed two-tube system, so I decided to do it my way. [by the way - I see some of you are wiring up your own 240V lights. This can be very dangerous and is not recommended. You could kill someone (yourself) and I believe that if it causes damage to your home (perhaps by causing a fire) you are not usually insured! - Buy off-the-shelf or get it done professionally and make sure it is sealed, or use low voltage - see below]. I took an approach I've never seen anywhere else and which was very very easy and very cheap. Because I didn't want to dangle 240V over my tank, I went down the 12V route. I bought two mounting sockets for tungsten filament halogen bulbs (I didn't buy the sealed spotlights, just the bulbs and a separate two-pin mounting socket). Cost about $2 total. The supercompact 240V/12V 50W electronic transformer cost me about $20 (bigger, uglier versions cost <$10). And the key to it all are the 12V, 10W & 20W ultra-white, polymer coated quartz tungsten bulbs (about $2 each). These naked bulbs are ultra-white light (colour temperature 3500K, the sealed dichroic ones are 5000K) compared to normal tungsten, you can see the difference. Because it's all 12V, the wires are very thin and easily hidden in the wooden hood over the tank and run down beside the external filter intake, the whole fitting stands about 25mm high and sits on top of my tank's glass cover. It cost me about $30, took 30mins to put together and looks pretty good. It does not give UV light like some tubes to make your fish really glow, but the Tetra's really shine when the angle is right. I started with 2x20W bulbs, but that was overkill, so I went to 2x10W & 1x20W (40W total). The other great thing about the bulbs is you can use them like spotlights if you add a reflective cone (I use aluminium foil). This allows you to create light sculptures, or shadow zones etc etc. I also tried to spice it up with a cold-cathode UV fluorescent tube that I had handy. But these have really low power (1-2W) and it made no difference. Has anyone else done something like this? Is there something I should know about that I don't? Everything is going great. The tank's now about 6 months old and lightly planted and lightly loaded with fish (~20 small fish).