I have no idea what to do now

[Chris1559]

I am having an issue with Hair algea. I have a 37 gallon tall using a canister filter. The tank has been up and running for almost 2 years now. I had a cyano problem earlier this year and got rid of it using Chemi-Clean (I regret that) but since then I have had an issue keeping fish alive so at the momnet I have no fish in my tank. I have 4 mushrooms and two small colonies of Zoa's. Bam Bam's which are doing really great and spreading like wild fire and a random colony I got from my LFS. I have some Hermits and Snails as well. I do not add any food of any sort in my tank and have not for over 8 weeks since the last fish died. I do water changes about 7 gallons every 2 weeks and clean my canister filter at that time as well. I only use RODI from my LFS for salt and freshwater. I'm running Marineland's Reef capable LED's for lighing. I run my lights for about 8-10 hours a day. I recently tried the 3 days of no light. I wrapped my tank in towels and ensured there was no llight coming through at all. When I removed the towels there was no change. I have read a bunch and have no Idea what nutirents could be used for the hair algea to still grow. Any one have any ideas. I am at the point of soaking my rock in fresh water for a few dyas then leave it out to dry in the sun for a few weeks and start all over again. When I test my water there are no paramatiers out of wack. Nitrates are reading at the desired levels. I have only been in the hobby since I started my tank almost 2 years ago. Any advice would be greatly appreciated. I spent 2 hours last night scrubbing all the algea last night when i unwrapped my tank and did a water change. Please Help!!

 

[Tahoe61]

Will need a phosphate level from your water source, not display water. Canisteres have a place in the hobby but if your having issues you might consider removing it or running it with some GFO.
What is flow like, can you add more, is there any surface agitation going on?
Have you thought about an Algae Truff Scrubber(ATS), or the addition of any Macro Algae?
Are the members of your cuc algae eaters.
Since the corals you have are relatively hardy then yes you could proceed with a 4 day complete black out but you need to get to the root of the problem.

GL

 

[MistaOrange]

When last have you tested for PO4, NO3, Mg? MOre the PO4 as GHA feeds off phosphates even if there's no light for a couple of days. Try to do a water change & test a day later but clean off the alae as it could give a false reading. Also rais your Mg to 1400 maybe a little more to combat the GHA...

Drying out your rock would just kill off any life in there & then you'll have to start the curing process all over again. Not really the answer to kill off GHA as phosphates would still be in the rock.

Hang in there it will suside but try to keep the nutrients low...

 

[NanaReefer]

How often are you cleaning & replacing the media in your canister filter?

 

[Tahoe61]

I do water changes about 7 gallons every 2 weeks and clean my canister filter at that time as well.

....

 

[Chris1559]

Thanks for the responses. I just recently switched like 4 months ago from bio balls to Seachem Matrix and stopped using the marineland carbon bags that are desigend for the canister and got my own mesh bags and use Seachems Matirx Carbon. I have not had a need to replace either of those since I switched to them. I do rinse them out using RODI Freshwater to get any waste or debris. I can't increase the flow of the canister. I will eventually get a sump but I am waiting until I do a tank upgrade and go bigger. I want to find the problem just not sure where to start. I know I am not feeding anything and I went 3 days no light and it was still there. I have scrubbed all the GHA off the rocks and the tank looks good now but if I am not feeding anything would that be more of a chemical issue then it is anything?