Macro Algae and SPS Question...

[BfishLpond78]

So I was reading through some threads about water changes, SPS and Macros. Someone made the statement that if Macros can grow then SPS wont do as well, assuming that macros are growing due to the abundance of nutrients in the water...PO4 and Nitrates....

My tank is an Deeb Blue 80 Gallon with a 50B refugium, loaded with macros and a 30 gallon sump, SPS and Zoa dominate...young tank less than a year so I know I dont have much to go on as far as tank maturity, but wanted to ask the question anyway...

Alot of people often claim when they have hair algae problems or some sort of other nusicance algae that they test their water and their PO4 is reading zero, and the most common answer is because the algae is consuming it all and its undetectable. Which to me I believe makes sense. Now flipping directions and you read about the massively successful SPS tanks that are overflowing with sticks and drowing in polyp extension who also claim that their levels are undetectable.

Now, is there a difference (assuming both test kits are undeniably accurate) between my undetectable levels and the other guy who isn't running some sort of macro algae to rid of nusciance algae?

 

[Reefing Madness]

Man thats a tough one to answer.
You get the negative positive in a tank with alot of Hair Algae, not a tank with just a bit of it. The HA does consume alot of Phosphates and would almost render the test to 0. Macros is the same way, alot of people use it in their sumps, and unless you have a huge amount of it, just like HA you would detect something, as it wouldn't be large enough to render it 0. The HA and Macros have to be of proportionate size to the tank volume to make them worth anything in removing junk. Now it won't take long for them to get that way, and thus we get into the size of the Fuge they are growing in to make it worthwhile now.

 

[skinz78]

I've always been under the impression that the PO4 test kits that we have available to us for home use are not accurate at all and the testing machines that are actually accurate costs $1,000's of dollars.

So I've gone with the assumption that if I have HA or other nusence algae in my tank I have excess PO4.

 

[Mrfresh]

Following
I'm very interested to see where this goes.

 

[chort55]

There are other ways of lowering those #'s besides macros. You can have a beautiful SPS tank with carbon dosing/biopellets etc. and have 0 macro algae. You can also have a beautiful SPS tank with tons of macros, but it does IMO go slightly hand in hand when you have macros that your SPS will do better when the macros aren't growing as much (provided they are otherwise healthy and getting adequate light) because there isn't as much excess nutrient in the water for the macros to grow or to slow the growth of the SPS.

 

[Eric B]

I never use a test kit anymore for testing low range phosphates as they are not accurate. I always use the more expensive Hana (Not the egg) or a Milwaukee low range phosphate checker. In the past test kits would show zero phosphates in the water but when testing with the low range checkers they showed higher levels in the water. They are definitely worth the money for testing low range phosphates if you want to keep sps, but there are probably many that do fine with test kits but I have had no luck with test kits for this test.