Advice on water changes for low light non co2

Hey guys. I would like to get some advice from you regarding my low light, non CO2 tank and water changes.

Here are the specs.

29 Gallon with about 1.5 wpg of light.

Flora - Java Ferns, Anubias, Lemon Bacopa, Java Moss, Dwarf Hairgrass, Rotala Indica, 2 Crypts (I think wendtii), Marimo Ball, Moneywort, Red Ludwigia Repens, Willow leaf hygro - Hygrophila salicifolia, Vallesneria (not sure which one), Brazilian Pennywort, Wisteria, Cabomba, Dwarf 4 leaf Clover, Mint Charlie, & Guppy Grass.

Fauna - 2 Mickey Mouse Platies, 6 Pristella Tetras, 1 SAE, 23 RCS, 2 Olive Nerites, 5 Red Ramshorns, 3 very tiny Mystery Snails and lots of MTS.

Substrate is regular gravel and I have added root tabs.

How often should I do water changes? Or how can I tell when to do them? After reading some stuff here recently, I think I have been doing them too frequently.

Also, if I dose Seachem Flourish one a week and excel 3 times a week, will that have an impact on when I should do the water changes?

thanks in advance.

 

Thank you for clearing that up. I think by me doing water changes so often, I have created algae. I have a little bit of what I think is Brush Algae and a couple of small spots of either hair or cladophora. I have a marimo ball, so I'm kind of thinking it's clado, but I'm not sure. Would you advise I remove the Marimo Ball from the tank?

I wish I could post a pic, but my digital camera broke. The algae isn't a major outbreak or anything, so I'm not worried about it. I'm removing it by hand, and yesterday I added the shrimp and SAE, so hopefully they will get anything I miss or can't see good.

I think I'll skip the excel dosing and just add some ferts once a week or as needed for anything not getting absorbed from the substrate. Or should I do an excel dose everday for a week or so to help combat the algae and then stop using altogether? Or would stopping use create algae again?

Either way, changing the water a couple of times per year seems scary. lol
I just don't won't the fish or other aquatic life to die or anything from bad water. Is there something I should test for to know exactly when I need to do the water change?

Sorry for the additional questions... Just trying to get it right.

 

Thank you sir. I appreciate the response. I guess I will go ahead and do the excel in hopes that it will get rid of the BBA that is popping up.