If like me you are a novice and you get a GHA problem, firstly don’t worry it can be easily dealt with. This is what I learnt then applied using the advice from this forum;
If you have GHA, phosphate & nitrate readings in the water body will give you a false low reading because the algae has already sucked it up. (HK FUEY, thank you for relieving my headache of confusion by teaching me this).
Get a good phosphate reactor and protein skimmer.
I know you don’t think you are but I can almost guarantee you are over feeding.
I now only use live or frozen and I pipette /target feed tiny amounts.
Get a good clean up crew. My emerald crab, tuxedo urchin, and spiny black urchin are great fun to watch. You need all those little critters such as bristle worms to eat detritus, and they are amazing to discover in your live rock.
With your CUC check those snails daily. Many snail types cannot right themselves, they need your help. In nature there is not glass walls to fall off, and the ocean currents roll them back over. If upside down too long they will die and dump all those nitrates plus more back in the tank. Unless you have a stock of hermits that enjoy a bowl of escargot.
I found getting the light right mind boggling at first but there is a fantastic thread on it in this forum, that will tell you all you need from which lighting to how much per day. Is there any sunlight hitting the tank?
Make sure you have the correct water flow for your tank to get detritus up off the bed and into your filter.
Physically remove GHA where you can.
If the GHA is bad fluconazole will definitely demolish it! But then you need to get all the nitrate that the dying algae dumps out ASAP with increased water changes once the treatment is finished. Don’t forget to look at your fine top filter pads / socks as they will need changing quicker than usual.
You could spend hundreds and hundreds on chemicals that put things up or bring things down.... or....do regular RO water changes with good quality salt and that will do it all for you. (Coral / anemone care is an exception).
Please be careful if you are carbon dosing and stick strictly to the instructions. I caused a bacterial bloom. My water went cloudy, my sand went grey, and my skimmer had a cardiac trying to deal with it all. I almost completely crashed my tank from an accidental overdose in one night. There will be a biological war if you get this wrong. If this ever happens though don’t panic; I did a 60% water change put activated carbon into the filter and everything went back to normal within two days. And keep an eye on your protein skimmer.
RIP my shrimps and bristle stars from that experience.
Check your nitrates regularly if they go up, do a water change. And be honest are you possibly over feeding?.... even a tiny bit?
Finally don’t stress, enjoy the challenge. You will learn so much from your research, and once it’s gone stick to what you learnt on your journey and it won’t come back!
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