help with my algae turf scrubber...

To my eyes that looks a lot like Cyno Bacteria (Red Slim Algae) to me-not an algae at all. Cyno will defenitly out compete any other algae for nutrients. Best known causes for cyno? High nutrients-poor lighting-low flow.
Still as long as your DT is free and clear of cyno or algae your good
Oh another thing-why is your Mag so high?

 

I suppose it could be a form of cyano... it sertainly looks like it but doen not feel like it. as I mentioned I have 2 x 36 watts and flow is at least 35 gph or more. No cyano in the DT just filament algae on glass. mag is high because on IO. I had a slow leak in one of my pipes and just kept adding salt to the system untiul I recently found the source of the leak and fixed it. IO is known for being high in MAG... although I have never tested over 1500 b4 I admit.

 

Something to think about-high Mag levels have been known to stunt the growth of algae.

 

woa... thanks for that. I always though that Mg actually helps plants grow. Like Mangroves... they need mg to grow. I guess microalgae is differant than macro??? anyway, I have no idea on how to lower mg but to do water changes. for me that would require a differant brand of salt. anyother ways in lowering mg?

 

Your using Instant Ocean right? Usually the Mag isn't that high in it. Many reefers choose to keep higher Mag levels as it makes it easier for corals to absorb the Ca/Alk by keeping them separate longer. I also know that these levels are used to kill the Bryopsis algae. I thought you might be dosing for it. I would get a second opinion on your levels. What test kit are you using?

 

first thanks for taking the time to inform me of all of this. I've been in the hobby for 15 years and had no idea about the bryopsis... thats why i love this hobby, you can always learn something. I read some RC threads about Mg and bryopsis. I had a small spot of it once but it thankfully didn't last. cam on a coral that I purchased. anyhow, I suspect that it may be my test kit (or at least one of them anyway). Red sea is showing levels off the charts at 1880 and and salifer it showing at mid 1500. called red sea as that is a new test kit and watched the you tube vids to make sure I'm testing correctly and I was. they are sending me a new sample test kit to insure accuracy of the first. if levels are still that high than I will know for sure. But the red sea kit is testing high on Alk, Ca and Mg... I have Tropic Marin for Alk and it too is showing lower results than red sea on alk. anyhow Mg i think is high. although I won't take any action untill this is verified. I will test a fresh batch of IO tonight and report back ASAP.

 

ok here are the results on a freshly mixed Instant Ocean saltwater (***existing bucket***);

Tropic marin Alk = 6 dkh
Red sea Alk = 9.1 dkh

Red sea Calcium = 550
Salifert Calcium = 450

Red sea Mg = 2100 (woa)
salifert Mg = 1650

so based on these results I believe a few things are happening...

1. there is something up with the red sea test kit as they all show high results
2. Instant ocean as i suspected and tested in the past shows very high Mg , spot on Ca and slightly low Alk if you only look at saliferts and tropic marin results and you ignore red sea.

Instant Oceans results are definatly off and what I do is make adjustments to the tank by adding baking soda, dow flake and epsum salts as needed to get levels where they need to be then I turn on my reactor after than I only need to make changes after large water changes only...

I'm going to crack open a fresh bucket of IO just to make sure its not an isolated bucket but again I remember testing IO years ago and had similar results, cal is good alk is always low and mg is high always above 1300. I'd be interested if someone tests a fresh batch of IO to compare results

 

ok I opened up a ***fresh bucket*** of IO and here are the results:

red dea Mg = 1700 better but still reading way to high
salifert mg = 1350 right on the mark

red sea alk = 11.2 dkh
tropic marin alk = 9 dkh

red sea ca = 510
salifert ca = 450

something must have been off with the first bucket of salt... according to these numbers but the red sea test kit is still showing really high numbers for Mg so I'm going to also assume that the test kit is off. when i get the replacement from red sea i will post those resulots with the new opened salt bucket as well.

 

How big is your scrubber? As several differant sources for building effective scrubbers states that the flow through the scrubber should be 35gph per inch or screen. So if your screen is 6 inches long you should be using a pump that gives you a minimum of 210gph. Personally I would also change the bulbs to some standard whites 7.5k-10k. Even though algea does like lower light levels, it still loves normal light levels.

 

I tested the water flow using a 5 galon bucket and a timer. I have plenty of flow as the pump (2100 gph magflow hydrive) is the main for my tank and is t'ed off with a ball valve. i have to close the ball valve a bit to get it down to 35 gph. the screen is 13.5 wide x 6" high. I've been thinking about changing the bulb but how can I do it? I only have one on each side so if I switch one side and not the other than onle will get low light and the other high Kelvin light...

thanks for your imput but at this point its pretty obviouse that my salt mix is a bad batch and really high in Mg and other params which must be causing this issue allong with high nutrients due to high feeding and turning off my po4 reactor.