The increase in magnesium helps allow more bicarbonate as opposed to carbonate to stay free in solution thus leading to a higher pH but still a lower total alkalinity.

Algae sounds like a hair algae or byropsis of some sort, pics would be able to tell for sure. Chemically your tank is fine, leave it be

Ok thanks Ski. Here are some pics of my tank ( it is very green ):

Definitely looks like a hair algae. Not byropsis though, it's too thin. Are your big Astrea/Trochus snails eating it?

Slowly but surely they seem to be!! I really need some different kinds of snails apart from them, maybe get some trochus tomorrow or maybe a green emerald crab? What is your opinion on the emerald crab will eat things I don't want it to eat or will it in general be handy?
I have alot of turbo's at the moment and they don't seem to be doing a great job!!!!! How long does it usually take CUC to clear algae from the tank?
Thanks Ski

Well just tested my tank again all readings are the same except the KH has decreased again to 11.8. Hopefully it will start levelling out soon!!!!

Astrea snails are good algae eaters, also blue leg hermits love the stuff . Mythrax crabs are good to have around, and apart from having a liking for any small clams that are in the tank, they have never harmed any of my corals or other livestock in the tank. They will nibble on weed from time to time if there isnt enough algae to keep them going, but you can add dried seeweed to the tank to help with a blanced diet for them. They are good for clearing the places that the snails and hermits wont go, under rock work and in cracks etc.

Ok so a quick update with pics.
My test results today are:
S.G - 1.024
PH - 8.3-8.6
KH - 10.8
Ammonia - <0.25
Nitrite - 0
Nitrate - 0
Phosphate - 0
Calcium - 390
Magnesium - 1110

I am doin 15-20% water changes every week. The algae is getting better then worse then better etc!!!
The good news tho is where the algae is being eaten CORALINE is growing woooooo!!!

Here are some pics:
Full tank shot


Is this Calupera in the middle?


Feather duster


Nasarius


Conch


MORE ALGAE!!!!


CORALINE BABY!!


Sid the cleaner shrimp


Any comments or advice on how and when the algae will disappear will be appreciated!!!
Thanks

Hey Gordon,
A good tool to have in the arsenal against hair algae and the like is a hard bristle toothbrush, Scrub your rock every now and then and use a piece of airline alongside acting as a syphon. Have a bucket with a pair of ladies tights stretched over the rim and syphon all the gunk into this. Return the water to the tank.
I was plagued with the stuff in the early days but now its almost under control. Also your snails are Astrea snails whilst they are good they are nowhere near as effective as the proper Turbos. I have two in my Nano now and boy they can bulldoze that algae.
I am also in the process of finishing my under tank sump which will incorporate Cheato (Macro algae) lights will be on 24/7 ( 18w daylight energysaver bulb) which will starve the hair algae in the main tank. I also use Rowaphos to try and keep phosphate levels in check.
I hope this was of some help.
Regards
BigC

Thanks for the reply Big C I will try the toothbrush trick. I use ROWAphos and chaeto at the moment but the chaeto is not lit on reverse or 24hrs at the moment so is only growing very slowly. Hmmmm true turbo's. I can't seem to find any sites that sell them in the UK, can you recommend any?
SKI is this new tank syndrome or do I have excess nutrients, all my readings are 0 and I use RO water with a TDS of 0 for water changes? Also is there anything else on what Big C has said to win the war against this stuff???
Thanks guys

Hi Gordon,
Ski gave me that idea in the first place....
Cheato needs to be lit on the reverse or 24 hours in order to be effective by using up neutrients which would otherwise be available to the problem algae.
A for the Turbo snails bearing in mind they get big and really do bulldoze (make sure your rockwork is stable) Reef Critters have them and I have delt with them in the past. They are good.
http://www.reefcritters.co.uk/product.php?...=250&page=1
Regards
BigC

Hi Big C
Thanks again, I used the toothbrush technique today and it looks a little better, couldn't really get all of it but I did get a large majority off of the rocks!!! How often should I do this?
Big C how long did your outbreak last?
I am going to test my tank again in a minute for readings, if all are ok I might pop to the LFS tomorrow to get my first fish!!!!! What do you think?
Also I am being told by some other people to get a skimmer and it will definetly help get rid of the algae, what are your views on this? I am doing 15-20% water changes every week with RO water!!
I am going to also try and start lighting my chaeto 24hrs aswell see if that helps!!!

Just one more thing, I have some liverock in my sump which gets a fair amount of light from my display tank yet it has absoloutly no trace of algae on it???? Why could that be???

Thanks again great help

Hi Gordon,
Bear in mind I'm a newbie to salties as well and have gleened a great deal of info from the Gurus on here.
I would scrub my rockwork once a month, more regular in the early days. (once a week before waterchanges) This really did help as the CUC could not or did not keep up to the task. The Turbos are doing a better job. I knew I would need a sump at one point and I only wished I'd drilled the tank before I set it up. Anyway things are easier on hindsight. I have been assured that a sump filled with Cheatomorpha, with a water turnover of at least x10, good lighting on 24hrs per day. (18w 6500k daylight energy saver bulb) will cure the nusience algae in the main tank. I also plan to have a V2 120 Nano Skimmer in the sump as well. Going by what I've read and the many Aquarists I've been speaking to all say that this will do the trick. i had/have hair algae but nowhere near as bad as yours infact it was confined to one piece of rock and it always grew there even to this day. See my nano journal for the rockwall I built as a background. You'd expect that to get covered in algae. I can honestly say none has ever taken hold on this.
What I have learnt about marine tanks as opposed to the freshwater aquariums which I've kept many is with a marine tank you are always at it, cleaning, scraping, testing and waterchanging to name the most common tasks.
Keep on top of it, is my advice for what its worth.
I originally wanted just a tank to house soft corals and no fish, then I guessed I'd need something to interest me and decided on a pair of clowns (they will be the only fish in my tank) I took the advice of stealhealr to go with the fish first approach to let the tanks natural bacterial colonies keep up with the increased bioload and take readings to see how things were going. The fish have been in one week and are really thriving, readings are much the same as normal except for a slight rise in nitrate nothing to worry about. So I would go with that and get your fish first before the corals. Try and get your algae under control first as feeding the fish and fish waste will also add to the neutrient levels which the algae can use.
The liverock in the sump is getting nowhere near the light intensity as the main tank.
Hope this was of some help to you.
Regards
BigC

BigC has some great advice. Only thing I'll add is that the tank looks as if it might be big enough for a Tang... If so, one would gobble up that algae real quick

Big C your a hero !!! All this advice is really helping. I will see how the algae progresses where I brushed it off in the next few days. HMMMM a tang I thought that they needed alot of swimming space?? Or maybe I could get a small tang and give him back once he has eaten the algae and got too big for my tank?? What do you think? Do all tangs eat any algae?

Well I have just tested my tank again and the KH seems to be levelling off around 10 but will test again tomorrow! My PH still fluctuates about .4/.5 during the day due to all the photosynthesis thats going on. Will go to some LFS tomorow and see what fish stock they have. Looks like I am going to be battling this algae for a while with the toothbrush!!!!

More pics tommorrow!!!

Thanks for all the info

You are not alone!
Good call from Ski though regarding the Tang. But still the underlying problem will persist untill you iron out all the causes.
Regards
BigC

So if I find a small tang tomorrow it will be my first fish. Are there any species of tangs which don't eat algae or will they all eat algae? I havent read that much about them as I will not be keeping one long-term? I like the look of the yellow ones?
Anyhelp will be appreciated


Thanks

Some individuals are picky but most species should eat that type of algae. Yellows will likely do so. BigC is right, the underlying nutrient problem (which is likely left over decay from original dieoff) will still be there, but in your case, the problem is really only one that requires time and some scrupulous use of a refugium and GFO.

Well I have had a good day today!! Firstly I have a small yellow tang as my first fish and she/he is settling in nicely!!! Will get pics later on. Also I got a job at the place where I got the tang from!!! WOOO! I also have my chaeto now lit with an 18W 6,500K freshwater lamp!!!! Hopefully I will now start seeing the benefits of the chaeto and an algae eating fish!!!!
Thanks