Canister Filtration for FOWLR

[pottersguy]

I have a question for everyone regarding filtration for my 150 gallon FOWLR. I currently use 2 fluval canisters for my tanks filtration (as well as live rock, approx. 150 lbs.) I know folks have said that canisters can lead to high nitrates, but the nitrate test kit I use says levels below 110? (can't remeber the unit of measuement) are safe for freshwater and saltwater fish only setups. When I test my water I'm usually around 50?-60? on the test kits scale. I also have a Aqua C Remora Pro protein skimmers that hangs on the back.
With that being said, I looking for opinions regarding the setup. My fish have always been healthy and the systems been up and running for approx. 1 year. The only problem I do have is green cyano? that will grow on the sand substrate although it is not excessive.
Any help or tips for improving the setup would be appreciated.

 

[i dont eat fish]

My 2 recommendations to you are to get a better test kit and do water changes until you can get those nitrates closer to zero.

Although a little nitrates aren't all that bad for fish, no nitrates is better for them.

And I recommend salifert for test kits. I and many others on here swear by them.

Since you are getting algae, I also recommend testing for phosphates.

 

[pottersguy]

I believe the test kit I use measures in mg/l. Is that the same as ppm?
Also, I use RO water with Instant Ocean salt. I'm assuming they don't contribute to phosphates, what else could be causing phosphates in my water?
Thanks

 

[i dont eat fish]

Yes mg/L is the same as ppm.

Phosphate article

Nitrate article

These articles have helped me understand a good deal about both nitrate and phosphate. They are from the chemistry section.

If I were you I would probably upgrade your skimmer to help also. Do you have a sump?

Also, how often do you clean the sponges in your canisters? I clean the sponge on my overflow at least once a week, sometimes twice. Bacteria can colonize the foam and create nitrates.

Also, adding a DI canister to your RO water will decrease phosphates even further, if your water is introducing it.