balancing ca alk and mg with algae issue

Having issues with my water parameters still. Before my ca and alk were both low, now that ive raised them, i've also raised my magnesium too high. On a side issue, i don't know if its related, ive had a red/brown algae bloom thats started taking over the rocks. The red algae is in the form of hundreds of dots on the back glass that is now on the rock work. I read several threads and and felt the algae to find its not really slimy. The pieces are very small, and seem to wipe off fairly easily from the glass.

Questions i need help with are how to bring the mg down without messing up the ca/alk too bad, and how to clear up this algae. Tank parameters as of this morning. please help
90 gallon tank 10g of water in sump
have been dosing esv 2 part ca alk
ph 8.3
am 0
nitrate 0-5
nitrite 0
phosphate 0
ca 390-410
alk 9.5dkh
mg 1650-1700
sg 1.0235
If needed, the livestock is only two 1/2 clowns 1-3/4 tang, 10 snails, 10 hermits and a 1 inch toadstool, and some small zoa's.

To make a small attempt to help, i went to the trusted local fish store and decided to do a 5 gal water change, changed out the 8 wk old carbon and have stopped dosing the 2 part.

 

How long has the tank been set up sweedish?


IMHO that Mag level is not a major problem and you can let it come down through utilisation over however long it takes - no need to do any additional water changes to bring it down rapidly

many people have elevated Mag levels even in excess of 2000 with no visible detriment to the livestock ( used as a means of combating Bryopsis algae)

Steve

 

the tanks only about three months old, its not my first tank. I had a great diatom bloom, and am now worried about this red algae. I've had red cy algae before, and in the past found high phosphates to be the problem. but this time, everything seems to be in check water wise, so im stumped

 

get some images up for us Sweedish so we can try and ID this algae



Steve

 

That's exactly what I was going to say.

 

ill try and get some, later in the day as the wife has the camera. Its not too horrible yet, but its spreading quickly. everyday i turn the lights on theres noticably more. I forgot to add the flow for the tank it has a mag 7 return from sump with that does about 500gph with the head height, a mag five powering a single pipe with no head, and a koralia 1050, the water really moves and theres not really any dead spots. Ill work on pics later tonight, i have to go to work soon

 

any of the equipment new and recently added?
any possibility that you may have added a new source of silicates and are experiencing a secondary diatom bloom?

the images should help
also what lighting do you have? I assume its only 3 months old same as tank but if it where old lamps or tubes that sometimes accounts for algae blooms

you dont mention tank size? thus its hard to ascertain if the flow you describe is low, moderate or high

Steve

 

Contrary to some belief, flow has little to do with stopping or accelerating bacteria growth. You are showing no phosphate as it is being utilized. I would add a phosphate reator with graular ferric oxide and would also treat the tank with "Red Slime Remover" or "Chemiclean".

 

Now, is the algae red or is it purple? could be the start of coralline...

edit: nvm. saw that the dots wipe of fairly easily...

 

Its a 90 gallon
4 48" t5's all geissman and a fiji purple only 6 weeks old
Only new things added were 10 snails and 10 hermits, and now that i think of it, the tank turned a little milky hrs after adding them.
no new or recently added equipment that hasnt been with it from the start at 3 months ago.
Now that i look at it closely, there seems to be very little red which is spotty and may be the start of coraline
the stuff on the rocks is more brown, and may very well be a diatom bloom, as it is very faint in the sand also