DIY Marine Tank Automatic Top Up

[sophos9]

Hi, I want an auto top off kit for my marine tank however cannot afford the ones in the shop so I've set about building my own...

The idea is to have coloured LEDS indicating status, so green for powered, amber for topping up and red for manually switched off or a switch out (is it possible?)

Here is the plan, I'm OK with basic electrical - basically, I'm looking to run a 12vDC around the 2 switches into a relay which will activate a mains powered Eheim 300 Compact Pump, I want to leave it switched on all the time so it gets little and often. I also want a switch to deactivate the level switches for water changes so I've incorporated one it

This is the rough plan, I've ordered all the parts and will do a comprehensive "how to"

**broken link removed**

So for all the sparkies out there, can you help on how to get the LED's to correspond to the requested state?

Many thanks

 

[richard.c]

Hi,

Its fairly easy to fit the green and amber leds across the 12vdc psu and relay coil, just buy a 12v leds, if available, or standard leds and resistors.

To make the red led come on, just use a double pole, double throw switch and connect the led to the second pair of contacts.

For well proved,simple top-up devices, and a lot more, have a look at the following sites -

http://ozreef.org/diy_plans/
**broken link removed**
http://www.masa.asn.au - you need to log in to this forum, but well worth it
as they have plenty of diy units.

 

[sophos9]

Hi, thanks for the reply and links!!

Can you advise whats likely to happen if the relay fails and are there any safety concerns from the simple diagram?

Kind regards

 

[sophos9]

Just realised, the red LED intention is not right in my post and diagram.....

What I would like to do with the red LED is indicate when one of the switches are open and one is closed (indicating a malfunction...)

Many thanks

 

[sophos9]

Is the 'amber' LEd across the right coil numbers? If no, can you let me know what numbers it would need to go across?

Thanks loads

**broken link removed**

 

[Speakerguy]

Those Tunze Osmolators are ridiculous, aren't they?

 

[Pommie]

That diagram looks dangerously wrong to me. I assume that the relay is a change over relay and the mains should go to 4 and 5. This isn't however as dangerous as having a level (float) switch connected to the mains

Why don't you use a 12V wall wart and power everything from that? It will be much safer.

Mike.

 

[sophos9]

Those Tunze Osmolators are ridiculous, aren't they?

Crazy stuff, all the stuff I need to build cost me £35!!

 

[sophos9]

That diagram looks dangerously wrong to me. I assume that the relay is a change over relay and the mains should go to 4 and 5. This isn't however as dangerous as having a level (float) switch connected to the mains

Why don't you use a 12V wall wart and power everything from that? It will be much safer.

Mike.

Mike, thanks for the reply - the numbers on the coils do not correspond to the actual relay itself, I put them on there to ID where the amber LED should go. The problem is I need 240v for the pump that will stir the water and additives.

This is **broken link removed** I'm using I've read some stories of float switches melting

Apart from the coils which are not representative, do you have any additional comments on safety and LED locations? How can I make it safe in the event the relay fails short? As you can see, I'm new to this

Many thanks

 

[sophos9]

The relay connection is as such

**broken link removed**

I presume that the 240ac goes over 4 and 2, the 12dc goes to 3 and 5?

Someone please help...