I have had confirmation that my Aquarium Gardens order will be delivered today, so as planned I will drain off about 75% of the water this evening, plant up the MC and refill the aquarium. It's actually come at a good time as I have some detritus in the tank that needs to be syphoned off. I fed a couple of algae wafers to try and stop the Amanos eating the plants, but this resulted in a bit of a mess in the tank last night. There was quite a lot of it spread over the sand at the front, more swirling around in the water column and as the Corys rooted around in the sand it was sending more and more up in to the water.
This made me realise that flow in the tank is just not what it needs to be right now. The algae wafer particles were just swirling round and round in the left two thirds of the tank, but hardly any of it was getting to the right hand side where the inflow for the filter is located. Therefore, it was just circulating and not getting removed from the aquarium. I have been trying to use the skimmer at the back right to supplement flow across the back of the tank and this does help, but with such a small outflow and the flow reducing once you get a day or two of mulm in the sponge, it's not very effective.
I have therefore placed an order with Aqua Essentials this morning so I can try and address the flow. When I was attempting to change the location of inflow and outflow, the problem I had was I was restricted by my hose length. I also had the restriction that the holes I cut in the side of the tank suited the previous setup and are both towards the back right. The rigidity of the hose that I had bought from eBay meant that I could not get the pipes to stay upright due to the hose pressure. I therefore ordered 6 metres of the superfish 16/22 hose from Aqua Essentials to have a try with this. Some of the reviews say it was very flexible, the downside being that it can kink, but hopefully I can make this work.
I also ordered a Hydor Koralia 900lph circulation pump. I like the sound of this, a good boost to my flow, but a diffused flow so hoping it does not blast things around too much. I'm not sure on the placement of this yet, it will require some experimentation at the weekend (if it arrives in time). I have a couple of theories at the moment, I'm going to take alto's advice of trying the filter outflow pipe further forward on the right hand side so that I get flow across the front of the tank then it should turn over the left end towards the back. With the violet directing the flow downwards, I may put the Koralia next to the outflow violet to boost its flow, but have it more directed horizontally over the tank above the flow from the outflow. My other theory is that I could replace the skimmer at the back left with the Koralia to try and boost the flow around the tank as it comes round that left hand side. If I do that, I may keep the skimmer in the same place to contribute to this flow, or possible move the skimmer over to the right side to increase flow from the outflow. Hopefully with one of these methods I can get a good circular flow going around the whole tank.
Although I do seem to have good CO2 levels in the lower flow right hand side of the tank, I am not certain I am getting good ferts distribution. The dosing pump dumps the ferts in just behind the violet pipe at the moment, but one thing I have noticed when dropping some flake food in there is that there is very little flow in this area, the violet draws in water from around and above as the flow comes out, but not from behind. When I alter the flow with my new Koralia and hose I will have a re-think on where I introduce the ferts to ensure they get picked up and distributed.