What gets me, is when did Mg start becoming a supplement? 10 years ago nobody even heard of dosing, and there were a lot of awesome tanks out there. And for me, I guess my levels measure fine due to the large Ca reactor I run. But I've never dosed and never had a need to...

lol are you shaking your fist as you say this, old man? :razz:

I agree tho, 10 years ago there were a lot of nice tanks out there that to my knowledge, weren't dosing magnesium. However, my tank wasn't one of them and since dosing magnesium (amongst other things), now it is :wink:

Have you ever thought about having your water completely tested? I don't know if that would help but it might shed some light on things.

http://www.aquariumwatertesting.com/

I thought there was a canadian version of that company but I can't seem to find it.

The canadian version of aquarium water testing is out of business.

How are you checking P04 and NO3?

Something is fishy.....I had the same thing on my old 90g BB tank. My N03 was 20-40ppm.....algae didnt grow though and p04 was fine using a high sensitivity merk kit.

I think my problem was I let the detrituis build up in the bottom and around the rocks of my tank causing a NO3 problem. With a BB tank you really need to keep it clean.

My NO3 is undetectable, and the bottom is really clean. I clean under the rock work with a powerhead. PO4 measured with Salifert and a meter. Both well into acceptable. Even Mg was 1350, so that's not the problem.

Christy, aren't you running a Ca reactor? Mine is apparently keeping my levels in mid 1300's.....

Perhaps the salt we used then, even the same brand had enough in it??

I cant see you having a magnesium problem if running a co2 reactor. When I did, using CaribSea media, my mag was always over 1300.

On the other hand, your co2 reactor, better named alkalinity reactor as you know, may be contributing to your calcification problem. Just a thought.

I know you've been back and forth with sand in the past but I'm going to speculate that if you add sand and give it some time you'll find an uptick in your growth rate. This is not to say that you can't have great growth and color in a BB tank but that in your present case it may help. The substrate could theoretically allow for increased zooplankton in the water column and thereby food for the corals. Some substrate will also provide surface area for the precipitate you are reporting having problems with in your pumps. If you notice some clumping you can stir the sand manually and replace a little with your water changes a la Steve Weast.

On the one hand I like substrate because it reflects some light and provides a "finish" to the tank and on the other I hate it because it really dictates my flow pattern with a higher flow tank. But in the end it's just a few hours of work to remove it if you really hate it. And it gets more fun every time you do it ;) (I've now been back and forth from SSB to BB 4 times in the last 2 years).

No, the reactor was offline when the sand bed seized up

Andrew, I wanted sand for that "finished" look, but sand is also a sink for crap and that wories me. While I'm comparing my old tank to new though, the old did have sand......

9 years ago I was measuting and adding Mg as nessasary.

Steve