I have a Fluval Evo which holds 52 litres. I had help setting it up, but I have struggled with first brown algae, and now green and red algae. I have been away a good bit and so water changes have been sporadic, and I have lost a large coral (can't remember the name of it). My friend who helped set it up is on holiday.
I tested the nitrates and phosphates today with salifert kits as the one I was using wasn't specific enough. The nitrates are 1 ppm and the phosphates are 0.5. I have tried to read around the topic but there is a lot of opinion out there.
I would be very grateful for a guide on what figures I should be aiming for and how to get there. I did a water change 4 days ago of just under a third of the tank and cleaned the gravel as I was syphoning it off. I have changed the carbon filter, and have a new biomax to put in. The skimmer seems to be working. It could probably do with stronger pump as the water flow isn't great. I have 2 cleaner shrimp, a boxer crab, an emerald crab, 2 clowns, 3 other small fish I don't know the names of, 2 nasarius snails, 2 hermits, and a mine urchin (which is a nightmare and is going back to my friend once he is home!). I really don't want to lose the fish but am at a bit of a loss.
Many Thanks in advance for your help.