My first try

The tank has been running for about a year now and everything was going ok.
I had to remove a lot of the plants to get all the guppies out so I did a re-scape.
Stocking: currently has about 40 neon tetras 10 black rams and 10 gold rams
This is my first planted tank where I have pressurized co2, fertilizers, high light.

After


Tank: 6'x1.5'x2' 135 gallon
Light: a old t5ho fixture 4 bulbs 54w x4 4 foot in length 8 hour photo period
Co2: Co2 reactor about 6 months ago. Then I added a second line to the co2 to add a diffuser back inside the tank last week (unable to get a full drop of 1 ph) ran 2 hours before lights on turned off 1 hour before lights off(9hr).
Filtration: is 2 old school hobs and a large sun sun filter that pumps through the reactor
Fertilizer/substrate: I have been using Green leaf dry fertilizers and running inert sand substrate

• GLA EDTA Micromix (M)
• Potassium Nitrate (KNO3) (N) (this I had to stop dosing)
• Monopotassium Phosphate (KH2PO4) (P)
• Potassium Sulfate (K2SO4) (K)

I have been dosing 1 teaspoon of K&P on even days and 1 teaspoon of M on odd days. Water change once a week sometimes only 30% not the full 50% however
I did stop adding the N as my nitrates were going threw the roof

my water parameters are as follows:
Tap
ph 7 this varies from about 8-7 through out the year (city water)
kh 4
gh 4

Tank
ph 5.5 lights on ph 6 lights off
kh 3
gh 4

I have been reading in to the relationship of gh kh ph and co2 and have been buying all the test kits I can get my hands on so far. I have fresh water master test kit so ph, ammonia, nitrite, nitrate, kh, gh these are the test I have so far I have also got a tds and ph pen however I question the accuracy.
so I'm looking in to a better way to test ph in order to better get this co2 dialed in any suggestions?

The tank has never been fully dialed in at this point however it was growing good and starting to look great but it has always had some sort of algae going on and I have not been the best with the dosing and water changes I will admit. So I'm trying to get better and learn more that way I could achieve a really nice tank! as so many plantedtank.net user have! I feel like I'm close just something is off or I'm having a hard time finding a balance so I'm hear looking for suggestions and to learn how to grow plants and to find out what I need to change to get a nicer looking planted tank.