KNO3 is an harassment to BGA according to Barr, nothing special. He didn't really specify any numbers. Any amount you throw at it will harass it. This is a bacteria, remember? Yes you could mix a concentrated amount in a spray bottle but there is little point. If you have access to an area during water change it's just as easy to put the powder directly on the spot and scrub. But that's for extreme cases. For normal cases one just needs to increase the KNO3 dosing.
I should mention that the filter is new. I had previously been running the JBL 1501e which is rated at 1400lph but it was just too strong. In between this (before I purchased the Fluval) it was just the ehiem skim 350 (300lph) and I suspect this is where my problems began.
Aaargh
...CJ, when you discover that your filter is too strong there is no need to buy another filter. Too much flow is a good problem and is easy to fix without spending money. There is a simple principle of hydraulics that is normally a problem for most folks, but in cases like this, can be used to advantage:
When you have flow of any fluid (gas or liquid) through piping, whenever the cross sectional area of the pipe is reduced within the circuit there is an exponential reduction in the mass flow rate. This means that a small reduction in the diameter of the pipe causes a large reduction in flow.
So for example, say the inside diameter (ID) of the output spud on your JBL is 16mm which, according to them produces 1400lph (which is a bogus number by the way, but that's an argument for another day). If you then took your 16mm ID tubing and attached a connector that had an ID of 12mm, look what happens -
The formula for cross sectional area of a circle is Pi*R^^2 so for the 16mm diameter spud:
(3.14)*8mm^^2 = 201 sq.mm
For the 12mm ID connector (3.14)*6mm^^2 = 113 sq.mm
The flow rate loss will be, more or less, proportional to the reduction in the cross sectional area. So forcing the flow to squeeze through a 12mm restriction from a 16mm tube results in almost a 50% drop in LPH.
This is an oversimplification because it really is related to the amount of kilograms of water per hour lost, not really liters per hour, but you get the drift.
This problem occurs all the time when people attach an external reactor to their filter circuit and they don't realize that the reactor spud is smaller than their filter outlet spud, so they unwittingly reduce their flow rate massively and then run into problems. The same is the case if the Spraybar ID is smaller than the filter output spud ID. Anywhere in the circuit where the cross sectional area is reduced will reduce the flow.
So in your case, all you really needed to do was to use a thinner spraybar or use a hose barb plus smaller tubing to reduce the flow. It was not necessary to spend money for another filter.
I admit, it’s the nutrients I have been fearing and I needed to let go.
Yes, the tighter you allow this fear to grip you the more control of the tank will slip away. I've been seeing this for over 20 years mate.
I have not been using a drop checker so will add that back when I get home.
You can use a DC, or a better way is if you have a decent pH pen you can monitor the difference in pH from gas on to lights on. It's a much easier and more accurate way to do it, but yes, the DC helps to give you a clue. Make sure that you use distilled water adjusted to 4dKH, otherwise you will always get a phony reading. Do NOT use tank or tap water.
Flow is actually well covered now and oxygen levels should be better.
Flow by itself does actually improve Oxygen levels. In an unplanted tank, in order to replace the Oxygen consumed by the fauna we need to agitate the surface via bubbles to allow atmospheric Oxygen to more quickly penetrate the water. In a planted tank, the plants and algae generate the Oxygen and improve the water column content. The flow then helps to distribute the Oxygen. Too much surface agitation actually dissipates both the Oxygen as well as the CO2, which is needed by the plants to produce Oxygen.
At night, the plants and algae have a net consumption of Oxygen and in so doing actually compete with the fauna for Oxygen.
Lighting two t5 bulbs with reflectors. I don’t know if this is high output or the PAR rating. It was a cheap fixture as I didn’t like the washed out colours from the chihiros A-series (which does pack a punch) I ordered the new fixture to come with a lower K rating for colour but it came with marine bulbs. I think it’s adequate if not a little too much for my current co2 levels.
This chart is floating around in a few places and is a fairly good guide for non-LED fixtures. Again, nothing is super accurate, just a guide.
You can follow the curve labeled T5HO and follow it to the distance from the
bulb to the substrate. So lets say your substrate is 20 inches from the bulb. In that case you will be generating about 60-70 PAR and this is considered medium which is in the pink band. When you have poor CO2 and poor nutrients you really want to stay out of the yellow band, and you will have faster recovery if you stay in the blue band. If you have two bulbs then you multiply the PAR number by 2.
As you can probably guess, most people are way in over their heads and are using too much light. Whn you have Algae and CO2 problems, the first thing to do is to disable at least one bulb if you have multiple bulbs or find some way to reduce the PAR. Reflectors add about 20% to the PAR numbers.
I don’t have a lot of plant mass either which I am working on. I do have easycarbo so I can add some of that too.
I wouldn't worry too much about your plant mass. You need to fix the mass that you do have. If you don't fix your problem then you will waste money buying more mass because they will melt too. Add Easycarb every day, maybe even twice the bottle sugested, especially when you do a water change. Some plants don't respond well so just be careful. BBA do not like Easycarb so you can use this as a weapon. If you double dose you will likely see the BBA turn pink after a few days or so.
I purchased some more nerite snails yesterday to help with the algae and I’m looking to get some Amano shrimp too.
Well, my philosophy is that animals do not help you to fight algae. Algae is indicative of a fundamental infrastructure problem that you must fix using policies (such as not fearing nutrition) and using technologies that are effective. Also, putting more animals in the tank, especially those that are extra sensitive to things like Gluteraldehyde bombardment and CO2, is counterproductive. Sorry, I don't like this idea at all. Fix your problem first, then add your animals.
Cheers,
and if it was the Matrix I would go for the 'Plants by Clive' upload second after 'Jujutsu' 
