New Setup, Old Tank

Hello again.

I've attached a very basic layout of my new proposed setup, if anyone can spot a problem please let me know.

The water from the tank, going into the proposed filter will be syphoned and controlled by a basic ball valve (to safe guard against power cuts). The water will then be drawn from the proposed filter into my existing external filter before passing through the inline, external heater on the way back to the tank.

Proposed Filter

This will be divided into 2 sections with a gap at the bottom for water to move through. The water will first pass through sponges (mechanical), then plastic scourers (biological), then some old aquarium sand at the bottom of the filter higher than the gap. On the other side I may put some hardy oxygenating plants, with an old aquarium light above, in an attempt to remove nitrates. I may also put a small aquarium heater in here, to help my inline heater maintain a higher temperature, (essential for the discus a plan to keep).

My main concern here is regarding the speed of the water being drawn into my existing filter. As the proposed filter is lower than the main tank, will the reduced gravitation effect on the syphoning be an issue

Existing Filter

If my concerns regarding the syphoning to this filter are unfounded, I may have to restrict the flow of water out of this filter by using a valve. This will stop my proposed filter from running dry. I plan to fill this filter with more biological media, my old bags of ceramic noodles and bio balls.

I recently read somewhere that a filter is more productive when the flow of water through it, is actually reduced. Apparently a fast flow means the bacteria have trouble feeding on the ammonia/nitrites. Has anybody else heard this? Would more biological media, particularly after the plants in the proposed filter be redundant? Would it be a better idea to leave the existing filter empty to aid water flow if needed?

I really appreciate anyone who takes the time to try and understand my scrambled thoughts and basic layout. All comments, ideas and constructive criticism will be valued, Thanks.

Stuart.

Here is a link for overflow kits that is a) in the UK and b) doesn't require drilling the tank.  Using an overflow is more robust than the use of a ball valve in the sump.  This is liable to failure and then your tank will empty over the floor.
http://cleartides.com/userimages/procart26.htm

Personally I really don't like the cleartides solution. Very bulky compared to what I wanted.

I think I may have just thought of a way of making the diy overflow work though.

More details to follow.

My main concern here is regarding the speed of the water being drawn into my existing filter. As the proposed filter is lower than the main tank, will the reduced gravitation effect on the syphoning be an issue

My understanding of a canister filter is that it's a sealed system and works on the principle that both inlet and outlet pipes form a continuous water volume starting and finishing at the same height. In other words the two pipe are in equilibrium, with the impeller providing just enough energy to help draw water through the filter media.

Have you tested your canister filter to see if can lift water to your tank without help from an inlet water column of the same height.?

Never let a 6 year old play with your alarm clock, or you too can be awake at 2:45am.

Mould grows in damp places that have access to oxygen and your emerged wood will be perfect. The last thing you want to do is put any chemical on it so you can either submerge it completely..... or chop off the offending bit. You might be able to grow something on it that will cover the wood and out-compete the mould, but I wouldn't know what to suggest for that.