Warren

Pumice works great but can cause brown algae for the first few months after adding it to the filter. It can have a lot of silicates in it and red and brown algae like silicates. It can also contain some heavy metals but a hydrochloric acid bath followed by a good chlorine rinse then lots of freshwater to finally clean it up helps get rid of the heavy metals and any organic matter stuck in the pores. I used to use it a lot and had about 25L of it in a filter on my old fishroom. Works great. Seachem sell a product called De-Nitrate which is simply processed pumice...

Warning, this thread has degraded into the all to familiar name calling childish banter so typical in the saltwater section. You are in danger of receiving warnings. Cool off, pull your heads in and return to helpful posts only or don't bother posting at all (goes for everyone)...

2 weeks ± a bit.

I've used good old garden dirt to kick-start the cycling process. Lets face it, the same denitrification goes on in the garden. Apart from making the water dirty for a short time it seems to work really well... You need the moist dirt from 25mm or so under the surface - where the air still gets to so the bacteria are aerobic and not anaerobic.

Yikes!! Yeah, Napier takes it's art deco buildings pretty seriously... Give me a call if you need a hand with anything, Napier is a pretty small place so I'm only 5 minutes away. Lets face it, anything in Napier is only 5 minutes away!!

Have fixed the edit function - I think :-?

They sure are. I had some many years ago. I kept them for about a year, then returned tem back to the river where I caught them. They had grown quite a bit and also bred so the three I caught were 20+ when I returned them. I discivered very quickly too, you need a very good lid or they are gone... One of the baby ones dissapeared and I never found it. I fed mine just about everything (flake, crumble etc) but they seemed to like the discus frozen food the best. They are garbage eaters so will eat just about anything.

It's never stopped me. I asked if I can bore holes on the proviso that any hole is fixed before I leave. In my last flat, the owner decided they were going to repaint so I jibbed up the holes and helped with the first coat. I'd put in many holes as there were 3 big tanks in the lounge (all over 600L) and I wanted to hide all the pipes. It all really depends how good your landlord is and how much work you are prepared to do when you leave the flat. Make up small frames as someone else has suggested. If there is air-gap underneath the carpet won't rot. Just brace whatever you make well so it doesn't pancake itself. The concrete blocks idea will also work well and isn't too untidy.

Yeah, we all suck at something so should be no-probs. Sorry, no pics. It was years ago and I don't use that system any more. It's a lttle bit difficult when you've only got one tank...

Na, easy to suck-out, I used to use something like this on two of my tanks with a pipe of 75mm diameter and it was no problem to remove all the air.

Pool filter sand is too sharp for the plant roots and will irritate the mouths of most fish. It is crushed stone with quite sharp edges. It's designed like this to help trap the dirt and be a better filter. Pool shops will tell you to replace the sand after so many years as it loses it's edge and is not as effective. You want 2-4mm gravel. Plasterers sand would be alright if you can put the sand over a fine mesh to remove the grit and very small particles so only 2mm and bigger stones are left. The grit and fine sand may pack down and seal off sections...

Really good advice!! Don't muck with electricity and water!!

There are other possibilities for what causes currents to flow but I'm pretty sure they will be dominated by any stray capacitance in the system...

It's capacitance. Mutual coupling between inductors requires two inductors and in this case the inductance of any device in the tank is tiny and the inductance of the tank is pretty much non existant. On the other hand, the capacitance from the conductors inside the devices to the water is many times more significant. Think of the conductors in the devices as one plate of the capacitor and the water the other. When you apply an AC voltage to the devices it capacitively couples to the water... I'm an engineer and I breath this stuff almost every day, trust me.

This requires a DC current to make it work. The current that leaks into your tank from the mains is AC, so no good...

Hmm, I expect a peltier chiller could cost about the same. I can easily make one very cheaply but then I have access to really cheap electronic parts through work (including the peltiers). I'm so used to getting the bits for really low prices I tend to forget most other people probably can't... Just quickly worked out the cost to make a peltier cooler for 300W cooling and 600W heating. For anyone who has to use parts available from the likes of Electronic Retailers, forget it and modify a dehumidifier. To make one properly will cost about 1.5 times the dehumidifier.

Sometimes you can't fix capacitive coupling but yes, trying to find the problem and fixing it would be a much better solution.

I know I'd rather have the current go to a ground probe if there was a fault. The last thing I'd want is to find out there was a fault by putting my hand in the tank and getting a major zap. I've had many good sized electric shocks but they would be nothing compared to a wet hand in tank shock... Even with a RCD installed, you still get a pretty good-sized zap before it trips. The response time on some is as long as 0.3 secs, an eternity if you're on the receiving end. At least if the RCD trips due to an earth probe, you are safe from a life-threatening electric shock. If you are worried about long-term effects of the earth probe, why not just use it when you want to do tank maintenance so the tingle doesn't annoy you?

That's the way. DIY it if you know how to I say!!

The long distance and very thin amount of water between the tank and sump with have virtually no electrical link. If the probe is in the tank then the sump may as well be disconnected as far as earthing goes and vice-versa... You'd really need 2 probes. Although, puting the probe in the same tank as the electrical devices should do the trick. You should only need 2 probes if you have electrical devices in both the tank and sump.

Difficult to explain but I'll give it a try. The AC mains voltage going to electrical items like pumps and heaters in your tank is alternating at 50 times a second (50Hz). There is insulation on the wires to stop the 230VAC going directly into the water and to stop accidental touching. The world of electronics is not ideal however and there are all sorts of nuisance effects. As the voltage is AC, changing 50 times a second from positive to negative to positive, some of the voltage effectively leaks across the insulation because it's AC. Normally this does nothing as there is no path for the voltage to go anywhere. When you put your hand in the tank, you provide a path for the voltage to return to earth. This causes a current to flow through your tank and through your body which you feel. The fish may also feel this but only when your hand is in the tank. What they feel would be much less than what you feel.

Sometimes the earth connection at your house doesn't have very good conduction to ground (like when it's been dry for a while). There is often a small voltage drop from neutral to earth in this situation. Having a probe connected to your mains earth or touching a screw on a light if this condition is present means the small voltage appears across you to the real earth when you touch it. It may only be 10-20V but you can feel this on sensitive or wet skin and in open cuts etc...

Sometimes pumps and heaters can capacitively couple a small current into the water. You should only be able to feel it in cuts or very sensitive skin. Any more than that indicates a potential problem.

Yeah, RCD's are really good. I won't work on any live equipment without one... It pays to get the type that doesn't turn off when the power is removed. Most of the cheap plug in ones reset if the power is removed (like when there's a short power cut). If you are out for a while when there is a power cut your RCD will reset, - no power to the tank... The non-resetting type still trips when it needs to but doesn't turn off in power cuts. Learnt this the hard way in my old fishroom.

That gravel looks like it has sharp edges. This can cause mouth damage to some fish. Plant roots are also better with smooth gravel.