DIY Autotop

[bloodlamb]

hi,

Just to share my DIY auto top up using Tunze Metering Pump.

First this is the adapter I used:

[bloodlamb]

The float switches mounted on some tunze mountings that I have lying around.

[bloodlamb]

The pail (for fresh water) with two holes drilled at the side for the outlet tubing (blue john guest tube) and power for tunze metering pump.

[bloodlamb]

This is the control box.

It is just a simple serial DC circuit.

It has an ON/OFF switch for power.

One red led for power on indication.

One yellow led for pump on indication.

One force pump on switch.

[bloodlamb]

A rough bill of material.

1 x strip board

1 x green led

1 x amber led

2 x 500 ohm resisters

1 x project box.

2 x switches

4 x RCA connectors

Wires.

Total above about $20

2 x float switches wired in series ($18 ea)

1 x Tunze Metering pump from Reef Depot.

Blue John Guest Tubing from Reef Deopt.

Tunze mounting hardware for float switch (already have).

Total < $80 for a operational system.

TODO: I have made provision to mount another safety float switch to cut off if the water level gets too high.

Most of the ideas come from the tunze osmolator.

The whole system works off 9V because the adapter could not handle the metering pump current load with 12V. Using 12V the pump would be able to push the water higer and futther which is not needed in this case.

Advantages of this DIY:

- Quite cheap compare to commercial system whose prices mostly do not come with a pump..

- Safe since only DC is used throughout. No high voltage (220V).

- I get a backup pump for my tunze osmolator.

Disadvantage:

- Not as many safe guards as commercial systems such as the tunze osmolator that I already own. For example it would turn on the pump for 10mins max.

- No build-in hysteresis. Hope the pump don't turn on/off too fast.

[bloodlamb]

Someone PM me to show them a connection diagram so I decided to post it here to benefit more people.

I feel that my design is the best for people with no experience with electronics. because it uses only DC and would not shock or kill you.

You can omit the "force on switch" if you want it to be really simple.

No complicated controls, basically the pump turn on when both float switches are turn on. You can use only one float switch if you want. The basic curcuit is just like a torch light (light bulb is the pump and float switch is the switch)..

The float switch turns on when the water level falls below it and turns off when water "floats" the plastic ring. I use 1 float switch to set the water level and one float switch much higher above the water as a safety cut off if the first float switch stuck.

You need to figure out a good way to mount the float switch. Don't use sucker.

In fact the simplest design you just need:

1. 1 or 2 float switches

2. DC low flow rate pump

3. DC adapter suitable for the pump.

4. Wires

1/2 can get brought from Reef Depot.

[boxfish]

the tunze float switch works on DC... great...

used to be told to connect one leg of float switch to the neutral...

so the on/off or contact depends on the uptrust of water ....

Do I need to seal/water-proof the float switch joints and wires?

if yes... recommended method?

[bloodlamb]

Best if you water proof them. I use plastic wire connector (the kind that has screws) and just block up the holes with blue tack after checking that the connection works.