I... I have always had some issues with algae/ high nitrates/ high phosphates. ...
I believe your asking the wrong question. Your asking about filtration and media being used. I think your question should be how do I control high nitrates, high phosphates and algae?
Wile filtration is an important part of this, it is much more likely that your problems are being caused by other things. I've posted this before, but it's worth posting again. It is a summary on how to control algae.
DaveK's Standard Lecture #2 - Algae Control
Algae control comes down to controlling nitrates and phosphates. If you have a problem with algae it is because these two nutrients are out of control. Do not think that just because your test kits read zero or low values that you do not have a problem. In many cases the algae is removing the nutrients and growing. This is why there is a problem.
Here are possible sources of nitrates and phosphates -
Feeding, especially flake food and not rinsing frozen foods before feeding.
Using tap water to mix salt. Always use RO/DI water for this.
"Dirt traps" and "nitrate factories" in the system.
Low quality carbon can leach nutrients.
Low quality salt can sometimes add nutrients. This is unusual today.
Livestock load on the system
Here are possible ways to remove nitrates and phosphates -
Water changes. Change 1/2 the water and you reduce the nutrients by 1/2.
Skimming. Remove the waste products before the biological filtration need to break then down.
Nitrate and phosphate removal products.
Deep sand beds.
Refugiums.
Algae Scrubbers.
Each of these has advantages and disadvantages. Most people that control algae will use many of the above methods.
There are also other items that can effect algae growth rates.
Good clean up crew.
Other livestock that eats algae.
Low general water quality, especially when the readings are off.
Lighting, sometimes you can reduce it, especially in FO or FOWLR systems.
Old light bulbs. Colors change as they age and this can be a factor.
Water flow. More flow will often help keep algae down.
Manual removal. Very important, especially when there is a big problem.
--- end of standard lecture
I'd say the most common problems with algae control are feeding way too much, feeding the wrong foods, and not feeding correctly. Dry food like flakes or pellets contain a lot of nitrates and phosphates. Frozen foods should be rinsed in fw to remove the "juice". this can also be a big indirect source of nitrates and phosphates.
If your not using RO/DI water for mixing new water and for top off, I'd highly recommend it. Tap water often contains a lot of nitrates and phosphates.
to RS ! No blacks sponges in my RSM 250, just a square of white filter floss in the holder made for it, rinsed weekly.
I think you have the latest model rsm 250, they added a rsm brand media rack that comes with the rsm 250 now, I believe
