sorry i've not been able to reply as life's been a bit of a roller coaster recently.
Ceg you're right i didn't clarify much and was quick to jump to conclusions - it's a very low tech tank and really isn't run with plants in mind but i like having them there as the Goldfish are so messy it can't do any harm to have them around.
Lights are not on a timer so are literally on when i'm in and turned off when i'm not which can differ massively; no CO2 except easy carbo now and again and then a weekly dose of fertilizers if i remembered. Flow isn't great as the Goldfish are 'fancies' and wouldn't appreciate it. Roughly 30-40% water changes once a week. Knowing what i've learned so far from UKAPS I'd be surprised if i didn't have algae tbh!
I mainly had BBA and green spot algae with a small amount of brown algae that i removed every week; the BBA seems to be concentrated on the wood i have in the tank and the green spot and brown algae prefer the glass. The plants largely got off unscathed!
Thinking back i'd actually changed quite a lot around the time so it was wrong to jump to conclusions
- i'd switched from API Leaf Zone to TPN+ and missed the previous week's dosage
- i'd been quite lax with the easycarbo following a week where i'd been quite religious about dosing it daily
- i'd moved some of the plants around to accommodate the purifier
Anyway the purifier is working well as far as i can tell - I know you're not a fan of testing kits Ceg, but I never get any traces of ammonia or nitrite, whereas before i just to get tiny traces towards the end of the week when a water change was due. I've been doing 10% water changes just for my peace of mind (I still feel uncomfortable with nitrate being so high, but i'm sure i'll come around eventually). Algae has settled back down to prior levels since i've been more thorough with my dosing. Main problem I have is the snails crawling into the diffuser and getting wedged by the impeller so it makes a rattling noise but they're easy to remove, so more fool the snails!
To be clear I'm not trying to eradicate algae in this tank, it does no harm and the plants aren't really affected - in fact it's quite useful as it gives me an endless supply of fresh algae to feed the otos!