Oops, probably should have known...

[rocketeer]

Kind of long. You know how Ca and Alk run opposite each other? Low Alk lets Ca run high and visa versa? Apparently there’s a similar relationship between NO3 and PO4. I’ve been battling an increasing problem with cyano and hair algae. While my head was in the sand my NO3 and PO4 went to 10 ppm and .01 ppm (Salifert) about ten days ago. So I installed a DSB over the next week and did a 20% water change. Meanwhile I rearranged my rockwork a little. Two days ago NO3 was at 25 ppm and PO4 was .05 (Hanna Phosphate test). Ok, so I stirred things up and the DSB hasn’t kicked in yet. But at least I can knock down PO4 with GFO. Doubled my GFO and it worked! Yesterday PO4 was 0 by both Salifert and Hanna. But NO3 today was at 30 ppm! Tonight I was reading a forum on turf scrubbers and the author said he got both to 0.0 then repeatedly NO3 would go up while PO4 would stay at 0.0. To fix the problem he would feed heavily and they would both go to 0.0 again. The turf wouldn’t grow without PO4 and NO3 would climb. Feeding increased PO4 proportionately more than NO3 and the turf would grow and bring both to 0.0 again. And it dawned on me, I did the same thing with my GFO. The moral of the story is: Bring them both down together. How you do it, I’ll leave up to you. I don’t think I’ve ever heard anybody discuss this relationship before but it makes sense. Just thought I’d mention it.

Jack

[CoryDude]

This is new to me but I'm not a reef chemist. Do you have a link to the article?

[rocketeer]

Yeah,

http://www.3reef.com/forums/i-made/m...hin-51120.html

Page 11 post #102.

It's an interesting read. It gets kind of hostile. Year 2008, so it's kind of old. But it makes me wonder if turf scrubbers should have a more prominant place in our hobby.

Jack

[rrasco]

Interesting points. I believe I've had similar issues, with an ATS as a matter of fact.

[rocketeer]

The main objection people seem to have with ATSs is the "yellowing" of the water. Has anybody here used an ATS and scraped the screen outside the tank? The author says yellowing is caused by scraping inside the tank. Any opinions? (ok sort of a subject change.)

Jack

[Fracture]

We used it for a long while and always removed it to scrape and our water was never yellow. We will be putting one on each of our new set ups soon

[rrasco]

The main objection people seem to have with ATSs is the "yellowing" of the water. Has anybody here used an ATS and scraped the screen outside the tank? The author says yellowing is caused by scraping inside the tank. Any opinions? (ok sort of a subject change.)

Jack

I've never noticed any yellowing. I also wouldn't understand why anyone would scrape it in the tank. The point of the ATS is to remove the nutrients from the water, if you clean the scrubber in the tank, you are just releasing organics back into the system which would defeat any purpose of running the ATS to begin with. You're supposed to remove the screen and clean it. The only reason I could think people would clean them in the tank is laziness.

[Big_Pun]

so why does a turf scrubber work better than a big ball of cheato?

[rrasco]

so why does a turf scrubber work better than a big ball of cheato?

In theory, if you had enough chaeto and it had ideal conditions to grow, I don't think there is a difference. However, adhering to best practices with an ATS, I believe it is easier to create ideal conditions and promote algae growth. One of the differences between how chaeto would grow versus an ATS has to do with the ATS exposure to air, through either the waterfall method or the newer upflow scrubbers. I don't remember the mechanics, but I do believe the air plays a big part in an ATS's effectiveness.

[kkiel02]

so why does a turf scrubber work better than a big ball of cheato?

There a couple reasons. One is that micro algae like turf algaes go much faster than chaeto so it pulls nutrients out of the water column quicker. Two is that turf scrubbers use a variety of algae so some can pull out nutrients at different n ratios. Also to answer the question about yellowing I've done both ways of cleaning the screens and haven't seen any difference in yellowing either way. Hope that helps some , gotta go back to work