Hey Shaumei and welcome to TPT!
There are a few things you can address to with your aquarium if you want to continue it as a planted aquarium. The first decision you need to make is to decide if you want to have a low-tech tank or a high tech tank, this decision will be a factor is almost every other decision about your aquarium. Low-tech tanks get a bad rap, you can have a very vibrant aquarium with little maintenance and low costs of operation. Or you can go with a high tech tank and grow pretty much any plant you could want, once you learn the basics of how to control you light and fertilizers.
Right now with your current filter you are not getting enough filtration and this can be the cause of your tinted water, given the depth of you tank you should consider swapping to a small canister or a much larger HOB. It is a little unclear from the picture but it looks like you have your intake tube set really high, you are going to want to have that tube as close to the substrate as possible, in my 10 gallon (one tank I use a HOB on) aquarium I have it about ľ inch from the substrate. A canister filter to me will work best for your situation, you will be able to get more filtration, more flow, and with a canister you can split your intake from your outflow, which helps create better circulation in your aquarium.
I see you said you cannot put a bigger HOB filter on there and Iím curious why? If it is because it is too close to the wall just drain the aquarium until you can move it and move it out some, or if you donít have space with the stock plastic cover, you can get a cheap soldering iron from one of the big box stores for around $6 and use it to ďCutĒ the plastic, or you can use a dermil tool if you have one handy.
From the pictures you posted most of your low light plants look fine, they seem like they are getting decent growth and have a nice color to them. So you have the workings of a decent low the setup, but you will still want to increase your lighting, if you want to grow those stem plants to where they are more compact and not tall and lanky like they are now. If you want to stick with a low-tech setup you probably want to swap those out for something else. Another thing that would help would be to remove the floater, since you are in the bottom range of low light they are taking away a lot from what little light it able to get to the plants at the bottom of the aquarium. You donít have to throw them out you can raise a smaller portion in the 2-way breeder you have hanging in your tank now. If you want to continue with the low-tech approach you should get some root tab to dose your substrate with and with a low-tech setup you will probably only put 1 every 6-7 inches, and continue your Flourish dosing until it runs out, when it runs out just buy some dry fertilizers and use that, one of the EI package would last you a very very long time in a low-tech set up you will be using very little of the fertilizers but they will help you out a lot. You can use co2 injection in low-tech tanks on a low bubble per minute count, or you can start dosing Excel, you will get much better growth from your plants and deeper color.
A circulation pump will help you out a lot, throughout the day the plants will use all the nutrients and co2 that are around their leaves and this is why you need good circulation even in low-tech setups. You have some options here, if you donít want to upgrade your filter you can get a sponge style powerhead that will help filter your tank, increase circulation, and oxygenate the tank.
Now on to high tech.
If you want to go with a high-tech setup you will have to upgrade your lighting, and in doing so you will probably need to ditch that black top you have on there currently. This subject is debated all the time here on TPT, if money is not a factor go with a BML LED fixture, or if you want to go a more affordable route you can get some regular CFL bulbs in 5,500K, 6,500K, and 10,000K which are the spectrums most people use, this is the most affordable route and you will get a lot of Lume output. You can make your own fixture of get some clip on light fixtures, or use desk lamps; CFL will give you the greatest option of how you fixture will look and function. There are also 10watt LED flood lights that can be found on eBay, I have used the 10,000K version and it worked out fine for what I needed it to do, the fixture is a little bulky but I have seen people that simply mount them to a board and suspend them above the aquarium, or make a sort of wood box for the fixtures so you donít actually see them.
When swapping to a high-tech tank you will need to increase your fertilization, you will either want to do EI dosing or PPsPro, I have never done the PPsPro so I can comment on how effective it is. With EI dosing everything is pretty simple, there is now water testing, and no chasing parameters, and it is much cheaper than buying the liquid fertilizers in the LFS, a $20-$30 will last you well over a year. You are adding more nutrients than your plants can use and this will ensure that there is never a lack of anything in your water system, then at the end of a week, you do a 50% water change and this will reset the nutrient values in your water. You will also want to use root tabs with this kind of set up but will use many more; in my high-tech setups I use one for every 3-4 inches.
Co2 injection is necessary for a high-tech setup. You can use a paintball setup, they are a little cheaper start up price but they will cost you more in the long run due to the cost of filling the canister. Currently in my area a 20oz paintball canister refill is $4.50 after taxes, and a 20 pound co2 canister exchange is only $20, so if you do the math to get 20 pounds of paintball refills it will cost you $72, so you are going to instantly save $50 on co2 and you will not have to worry about it running out for a while, as to where I was filling up paintball canister up weekly on my 75 gallon high-tech.
There are several things you will need for your setup, a regulator, either single or dual stage will work, some tubing, a 1 way check-valve (stainless steel is best), a diffuser either inline or in tank, and a drop checker, to me a bubble counter is optional most regulators come with one attached anyways. You will want to get a regulator that has a magnetic solenoid, you will hook this up to a timer, and set that timer to turn on 45 minutes to an hour before your light come on and go off about 30-45 minutes before they turn off each day, and it will turn your co2 off and on for you, a solenoid is key to help prevent the growth of some types of algae, many of which grow when there is fluctuation of co2. The drop check will help you determine how much co2 is dissolved in your water and give more accurate information than what a bubble counter will give you. Right now inline diffusers and inline reactors seem to be the way most people are going, I am still using the old fashion setup with an in tank style diffuser. The 1 way check-valve will prevent water from back flowing into your co2 tubing and damaging your equipment; this is a necessary piece of equipment.
This is all I can think of right now, I am sure there is more and others can use this as a base to build off of to help you out. I will source some equipment and let you know the names, sometimes the mods here are strict on links.