Help me, details inside

Ok guys I'm laying it all out on the line for you guys to help me out. I have an algae problem, AGAIN. and I'm not getting much caroline algae growth. Here goes
Tank
Tank-75 gallon Sump-20 gallon, LR-110lbs some have 25% or so carroline algae other a few spots. Sand bed- 2". LR Rubble in sump
Equipment
Light- 2x250 MH 16,000 spec, 2x54watt Artic Blue T5. Marineland Penguin 330 HOB filter. Aqua Maxx Protein skimmer, 2 little fishes Phosban reactor, JBJ Wavemaker w/ 2x1,800gph heads, 1x1040 gph, Auto top off, 2x740 GPH pumps.
Livestock
2 clowns, 1 yellow tang, 1 emerald crab, 1 cucumber, 15 blue leg hermits, 3 red hermits, 10 snails, 10 Nassaraus, 1 turbo snail. 2 balls of recently bought Macro Algae
Maintenance
1 mag float used every day, 1just bought sand vac, (pH Up, Calcium up, carb hardness Up... All used to keep right params) instant ocean mix, phosban, active carbon filter pads, filter sock, 2 bags w/ active carbon, API Reef Master and Saltwater master(Calcium, dkH, pH, Ammonia, Nitrite, Nitrate, Phosphate)

My test have been coming out Calcium-470-500, dkH-6, pH-8.2, Ammonia-0, Nitrite-0, Nitrate-60 , SG- 1.023.
I just did a 25gallon water change 2 days ago as well. And just added my macro algae. I've noticed my LR now starting to turn greener and greener and some new spots of caroline algae. my glass grows a small amount of green during the day that I can see the snail prints right thru it.

So guys , input and a point in the right direction would be great!

 

I wonder what the age of the system is. Established tank or relatively new? Are you testing for phosphates? What are the results? Are you using RO/DI water? Is the water testing 0 TDS? Nitrates in the 60s is a contributor for sure. The hang on filter could be suspect in this mix of variables.

 

The nitrates are fueling the algae.

Is it a FOWLR? Is that the reason for the 1.023? Ca is high for that salinity.

dKh is too low. I keep mine at 10.

What's the HOB for?

It takes a bit to see the benefits of the macro you just added.

What does your phosphate test at?

 

How often do you clean the media in the HOB. That could be why your nitrates are so high. I would recommend getting your nitrates down and adjusting how much you feed everyday and maybe bring down the number of hours your lights are on a day until your algae problem is under control. I'm sure there are more experienced people on here to give you better advice, but that is what people have been telling me.

Good Luck to you.

 

That is what I was thinking too. How often is the media being changed?

Are you using tap water or RO/DI for top offs?

While you did mention your livestock, you didnt mention how much or how often you are feeding and what types of food are you using?

Next question is going to be what is your lighting cycle like, and how old are the bulbs your using & what brand are they? Is your tank located in an area where natural sunlight it hitting it?

 

May we please have an image of the algae or a FTS.

 

I also noticed he bought a gravel vacuum.You do not want to disturb the sand bed in a saltwater tank. This can lead to Nitrates and other toxins being released into the water column. When the sand gets compacted (OVER TIME)it is ok to gently stir the sand in small areas a little at a time but vacuuming the sb is a no no. IMO

 

I think these guys have pretty much hit every important spot. The only thing I would add is what type of food are you feeding and how often. If you are feeding frozen food always rinse it with RO water or Tank water before feeding it the fish, so you dont get all that extra stuff in your water and take your phosphates up. Also remember to trim your macro algae to export the nutrients

 

Okay, Im gonna guess at it, I see you have 2-250w mh on a 75g tank, I did'nt see a chiller in your details and no temp reading was given, i'm gonna guess your temp is 80+ by the end of your lighting cycle, if my guess is true you need to cool the water down and not let it get above 78 and your gonna say bullsh-- when i say put 60 more astrea snails in there. I like 1 per pound of live rock I would put over 100 if it was my tank, just watch one eat for a little while they are the slowest eaters I have ever seen, just a few cannot keep up with algae blooms. oh the purple stuff get a rock or two with lots of coraline alg on it turn your pumps off and with a ruff edge file grind the coraline algae over the tank this will give you a start And use something like purple up to give it a boost James

 

You need a Magnesium supplement if you are using IO salt. It has low levels of Magnesium, so you will have a very hard time keeping both Calcium and Alkalinity at the right levels without increasing your Magnesium. Some niussance algae don't like hard water, so having Caclium 420+ and dKH 10-11 will slow it's growth down some, as well as increase your coralline algae growth. Unless you maintain your Magnesium at around 1400ppm, you will have problems keeping Calcium and Alkalinity that high. I used to use IO salt, and if I remember correctly, it typically has Magnesium levels (ppm) in the upper 1100s to lower 1200s. You may want to think about increasing the salinity to 1.025, even for a FOWLR, as it will help to bring up the Calcium, Magnesium, and Alkalinity levels some before you even add any supplements.