Algae battle: how to proceed

[IHaveADegreeInMarineBioBut]

For the past few months, I've been dealing with this matting green algae. It's pretty easy to remove, but it just grows back in a day. I am not able to test exact phosphates/nitrates, though my water has always tested for phosphates despite getting distilled. I do a ~15-20% water change every week (since I started the tank a year ago; the rocks came from an established tank) and I just can't keep up with the algae.

I did get another light in the meantime, and I've been lowering it the past few weeks, but I don't want to upset my corals.

Should I increase my water change schedule? Should I try a different filter media? 
I'm just very frustrated 🥵
Thank you

[WV Reefer]

1 hour ago, IHaveADegreeInMarineBioBut said:

For the past few months, I've been dealing with this matting green algae. It's pretty easy to remove, but it just grows back in a day. I am not able to test exact phosphates/nitrates, though my water has always tested for phosphates despite getting distilled. I do a ~15-20% water change every week (since I started the tank a year ago; the rocks came from an established tank) and I just can't keep up with the algae.

I did get another light in the meantime, and I've been lowering it the past few weeks, but I don't want to upset my corals.

Should I increase my water change schedule? Should I try a different filter media? 
I'm just very frustrated 🥵
Thank you

Have you tried upping the flow in that area?

[DaJMasta]

A test kit for phosphate (maybe nitrate, maybe silicate) would be a good investment and wouldn't be too expensive, I recently bought a bunch of Salifert kits for <$20 shipped each in a whole slew of things.  A cheap handheld TDS meter could also help tell you if your 'distilled' water is actually as pure as it claims.

 

Manual removal is going to help, as the nutrients will be used up by the algae and then physically removed, but unless your food is just constantly dumping more into the system to promote growth, I would definitely suspect the water supply given that you're not using RO. or RODI.  If your distilled water really is clean enough, then making sure you're not overfeeding and continually removing the algae should eventually use the nutrient source up, though it can take time if there has been some built up in the system.

Worth mentioning that I'd strongly recommend an RODI system for water.  Not only for not having to make the trips and buy the jugs, but because you'll have consistently clean water as a starting point.  I picked up a 6 stage RODI (2 carbon, 2 DI) from ebay for $100, and you can get kits with mounting fittings for under-the-sink installation for not too much more.  That and a <$10 TDS meter will do wonders for assuring you that the water that goes into your tank is really free from contaminants.

[IHaveADegreeInMarineBioBut]

On 4/18/2021 at 3:08 PM, WV Reefer said:

Have you tried upping the flow in that area?

Yes! I actually got a new powerhead because of it. But i have to be careful because of my coral placement.

 

 

On 4/18/2021 at 3:10 PM, DaJMasta said:

A test kit for phosphate (maybe nitrate, maybe silicate) would be a good investment and wouldn't be too expensive, I recently bought a bunch of Salifert kits for <$20 shipped each in a whole slew of things.  A cheap handheld TDS meter could also help tell you if your 'distilled' water is actually as pure as it claims.

 

Manual removal is going to help, as the nutrients will be used up by the algae and then physically removed, but unless your food is just constantly dumping more into the system to promote growth, I would definitely suspect the water supply given that you're not using RO. or RODI.  If your distilled water really is clean enough, then making sure you're not overfeeding and continually removing the algae should eventually use the nutrient source up, though it can take time if there has been some built up in the system.

Worth mentioning that I'd strongly recommend an RODI system for water.  Not only for not having to make the trips and buy the jugs, but because you'll have consistently clean water as a starting point.  I picked up a 6 stage RODI (2 carbon, 2 DI) from ebay for $100, and you can get kits with mounting fittings for under-the-sink installation for not too much more.  That and a <$10 TDS meter will do wonders for assuring you that the water that goes into your tank is really free from contaminants.

I do have API kits.. but of course it's not as accurate as it should be. 
I just went to the water store and it is actually RO instead of distilled, but I'm going to run some tests on it regardless. 
I do water changes on Sundays and it's already taken over everything again 😣

[IHaveADegreeInMarineBioBut]

I'm still struggling with this.
I think the tank could be getting some excess sunlight from the back, so I'm going to add a panel. I'm still turning the lights down gradually and it seems to slow down how fast it comes back, but it's still there by the time water changes are due.

What would your thoughts be on using Chemipure? For such a small tank, I know it could potentially strip everything?