I completely understand the anchor worm stress. This is one thing I would get right before trying to take on the algae. Concetrate on one thing at a time, get it right and then move to the next. Algae is there at the mo, sort out the worms, then after you're sure its clear then you can move onto sorting out the algae.
The worms are most likely why you saw the gasping too. Nothing to do with O or CO2. I would question wherever you bought your fish as these are in almost all cases fish to fish transferred. Were they there before you bought some plants?
DO NOT use something like Interpet Anti crustation and parasite as that will kill off your beneficial bacteria in the filter.
Use Waterlife Parazin or Sterazin. This is fish, bacteria and plant safe and is a week long course if I remember rightly. Also bio-degradeable so it won't need flushing out after and the best thing is it won't stain your tank like some other meds such as Methylene Blue.
I personally would be using a Formaldehyde mix but that is pretty dangerous both to user and fish tank if wrong. Therefore I won't suggest that.
There are some good posts on here for anchor worms i.e. the procedure of a bath, then when the parasite is dead, removing the parasite with tweezers (yes with the fish out of the tank, then dabbing blue on the wound to help it heal.
You're right that I'm anxious to take new advice and I'm not quite the right person to be told one thing by one person/establishment and completely different thing by another person/establishment. It causes a hell of a lot of confusion and stress.
Indeed, however the way a planted tank deals with some parameters is totally different to non planted. What can prove deadly in a non planted tank can be a minor worry or even not a worry at all in planted.
Its trying to point out that they are 2 different systems is so hard. People have learnt rules and then all of a sudden the rules have changed. How can they change? Why have they changed? after all the only difference is that there are now plants in the tank???
You are saying 10-12 c02 bubbles per min is not helping the plants, whereas the instruction manual states otherwise. Well, who is right? I stuck to following the manufacturers instructions because I've heard once that turning the c02 up can cause fish to gasp.
Sounds better than them lasting a few days. I hope it isn't one of those little 95g cylinder sets for your sake.
Manufacturers make equipment, they want to sell it to you, they market it to make it attractive. If those cylinders will last a year they will suggest X rate. If you then go and say Mr X tells me that the bubble rate is ridiculously low they will say Do you believe Mr X or a laboratory full of scientists and researchers!!!
This happens all the time in this hobby. Aquarium lights are specially designed to a certain spectral graph that plants
need. YEAh right. Why do people who use shop lights still achieve the same results? Why do those who use nowhere near the 'pink plant growth K' get great results? I don't use pink, mine are pure white.
Why do drop checker instructions, whether they be from the Far East or from the companies with huge plant product ranges, suggest to use tank water? You will not find any of us using tank water in ours believe me.
Check out how many 'plant specialist' manufacturers promote heating cables. then check out how many hobbyists (and some of the most respected within the hobby) say Pffff Claptrap.
If someone is selling then they will market the item. If a scientist says there is a slight chance something may work, then a marketing department for that product will say it DOES work and IS DEFINATELY necessary. We could fill an entire sub section of misleading adverts.
The first 10 pages would be blurbs from hundreds of ferts that say 'contains everything the plants need' and then goes on to say' contains no N and P so therefore does not promote algae'
They put this statement on because at the moment there are still more believers in the NP causes algae than those that don't so they will sell more.
There are 2 problems with that blurb.
1 - It says it contains all the nutrients plants need when it doesn't. Plants need N an P.
2 - N and P do not promote algae.
When you look at something read the blurb, then research. That is a problem in itself because there are some that will agree and some that won't. Hard to tell who is clueless and who knows. Therefore search place like the barrreport, UKaps, TFF. You may get some dodgy replies but nearly always someone who has a full(er) understanding of the latest thinking will arrive in the thread and set the record straight.
Even then the 'latest thinking' may well be wrong but it will be further along the path to a conclusive answer than the former beliefs and of course thinking and science is always moving so what we think is right now may not be right tomorrow. There is no such thing as a conclusive answer as more and more research and study adds extra into the path and we move further along. If the conclusive answer is ever reached there will be no such thing as science anymore

Will this ever be achieved?
The only thing the CO2 kit manufacturer's instructions get right in the above statement is that turning the CO2 up too high will always make the fish gasp.
Yes it will suffocate them. Its nothing to do with O as some will say. It is purely suffocating due to the level of CO2.
Unfortunately for them they then fall apart as they can have no idea how efficient your system is nor the parameters. They should not be trying to suggest anything on rates because they cannot possibly design an 'average' when we are talking many different sized tanks with many different setups.
However what you put into the tank is not necessarily what you get out of it. this is a gas. If we forget about which kit it is and just consider the tank as a car (meaning the filter, circulaiton etc)
So if the filter, circulation are top notch then we'll call it a Ferrari. If the filter and circulation are poor we'll call it a ...... not so good car (don't want to upset any Renault owners.ooops) Now if you put your foot down to the floorw in a Feerrari you are going to get a much faster speed than with the ....Renault. That is if the Renault starts at all.
So If you inject 120bpm and I inject 120bpm then you may get not much change in you DC (i.e. not much increase in CO2 ppm)where I may be pudshing too hard and kill my fish. This can of course be the other way round too. this is one of the joys of planted. We can tell you how to setup the best planted tank. How to achieve the best results. How to perfect it. However you have to take that in and tweak a few things to suit your system.
I do have an internal Cayman filter but the water flow rate is not adjustable and the manual doesn't actually tell you the litre per hour rate. All I can tell you is it's a Cayman 05 internal filter and there is ample water agitation.
It has a flow rate of 350lph (link below.) Nowhere near enough for your size tank planted. I use a 200lph on my 10ltr. You need something in the region of 700lph or more. Something like a Fluval 3+ or 4+ would be much better.
http

/www.ferplast.com/bluwave_eng.php
As for the macro-nutrients, I've added some Nitro/Fosfo today.
Good but forget their talk of ratios. Just dose it. Someone else may use these products and be able to suggest quantities. You can always do larger water changes to remove excess if you're worried.
Your statement earlier (maybe on a different thread) was a little wrong.
If 1 million people say phosphate causes algae, then 1 person who doses way above the level that is suggested (say 5ppm) does not have algae, then the 1 person has proved the 1 million wrong. If it is true then no tank with 5ppm will have no (almost zero) algae. That is how science works. It only takes 1 proven positive to break the theory.
Government scientists (those very highly paid guys) still to this day say that the fertiliser run off is the cause of algae in our ditches and rivers. However they don't take into account that they are constantly dredging all the weeds from these courses and disturbing the silt.
The undisturbed 'flowing' water courses like streams don't have algae? they are almost crystal clear. Those rivers through towns and cities and ditches alongside roads have to be beautified because its unsightly. They can't have it both ways.
So there you go. We can add 5ppm of phosphate, show you we have no algae and also show the governement scientists to rethink their statements. They won't though as it is an easy way to please the eco-warriors who campaign against fertilisers so suits a government goal of appearing green!!!
I've also added 10ml of Pro-fito and since you're now saying there isn't enough c02 being added, I've supplemented the c02 addition with 2ml of Easycarbo.
You're throwing money away here. Why add liquid carbon to supplement pressurised that is too low? Why not just increase the CO2 itself. The plants can use it much more easily than the liquid C.
I want to be able to have a tank that doesn't have fast algae build-ups. If I get my c02 levels sorted and add ample amounts of micro/macro-nutrients and add 2-3 fast growing plants, is there a good chance I'll be able to keep the algae at bay? Only one of the plants is a fast-grower in the tank so I guess thats not helping things.
For a beginner ....yes it is best to start with fast growers as they will grow up, fill out space and outcompete the algae. I on the other hand start up with all slow growers if that is my plant choice. I have confidence in whatever method I choose for a particular setup and confidence in my ability to correct any problems if any occur.
edit: what level of c02 should I be aiming for in mg/L format? Unfortunately I've never assessed it's concentration in bpm, nor do I know what that means.
bpm/bps is not a concentration. Its not even a measure of anything. It is a visual guide. It is so the user can count how many bubbles per minute/second are going through a bubble counter. Once dialed in they can quickly see if it alters. Also when they change cannister they have a fair idea of where they should be.
The concentration in mg/L is ppm (parts per million) 30ppm is the standard. It is recognised as a slightly conservative safe level in that it is almost the maximum of CO2 that you put in without the fish being affected at all. 45ppm (50% higher) may kill everything. You are looking for a colour of vivid grass green/limeade to reach 30-35ppm which is where I aim for and I am talking about a breeding tank with lots of shrimp too.
With that filter being so underpowered you are going to have some troubles with CO2 though. Not enough circulation. You wither need a better filter or to add a Koralia Nano circulation pump or similar. that pump would add 900lph and get you up to a better circulation around the tank.
Your is a 120Ltr. Mine is a 125Ltr. they are probably actually the same tank but the manufacturers have decided on a different volume.
When I was pressurised I had a 700lpg external filter and a Koralia1 making 2200lph turnover (makes your 350lph sound a little small?.)
However you've sen how heavily planted my tanks are. For the amount of plants you have you won't need as much circulation. I had that because extreme plantmass makes circulation difficult.
So get the worms sorted first. then think about the filter. Then think about the CO2 plants and the whole setup. You will be addicted once it gets working and your fish will love you much more
AC