Are your rocks old? I experienced a time awhile ago where my rocks were leeching nutrients that fed a massive GHA outbreak.

My LR is maybe 2-1/2 years old and I fully cured it before I started this tank
I'm pretty sure my issue is not enough turkey basting

Hey Denny

Finally got a new test kit
NO2 is 0, NO3 is waaaayyy less than 2 and probably closer to less than 1

NH3 is 0

PO4 is now 0.02-0.01

Yikes... sorry to hear it's causing this much trouble.

Bah, I'm still in (for now) :wink: but with all of life's other fun I'll admit I've been a tad stressed lately

Ok that's not bad , fwiw rocks can only absorb and leach Po4 and not nitrates , nitrates are not bound to anything so if your rocks have been in your system for a long time and your running a P04 binding media then it's only a matter of time before they would stop its not a problem you would have for. Year unless you kept adding phosphates and not exporting them.

While I know the numbers are low the algae is obviously getting enough to get by ,you don't dose iron do you?

I had issues with bryopsis and low nutrients my po4 was always bear zero because of gfo but my nitrates were always above zero , still low but still there none the less.

While large water changes work its time consuming and expensive which is what i use to do , I now dose vinegar and no more bryopsis as well no more nitrates either. I have also not had to run gfo in a fair bit of time as now the bacteria have been able to keep it down as well.


Water changes are still important for other reasons but are a poor way of removing nutrients.....1 step forward...2 steps backwards.
Maybe set up a ats, denitrator or start carbon dosing to help keep down the lower amounts?

The worse part about our kits are ....they suck. Not s much at high numbers as we care less how accurate they are when things are Hugh but on the low side the numbers really aren't all that accurate.

So a little help from our oldest friends goes a long way;)


With gha it's usually very easy to fix but blackouts , water changes, cutting back on feelings etc are all things that help overnight but not long term. As time goes by things find there way back to where they were so you need a long term plan.

Import vs export

MB7 regime if you never want to see cyano again. And has many other benefits, too. Have not seen cyano for several years now since I started using it. I did have other issues with my tanks this summer (on the mend now) but no cyano.

Not intentionally, but ever since I started using this newest GFO from Concept my green corals have become super-green, so I suspect there's some getting in that way

Thanks for the other info Denny
I'm hoping that once the algae is removed I'll be able to baste the crap out of the LR

I'm hoping to get a grip on this without incurring another recurring cost

How much per year do you think MB7 would cost?

Costs me less than $20/year for a 230g system. Pretty cheap insurance for a guaranteed preventative, if you do it right. Plus as I said, has many other benefits in your tank. Keeps the water very clear, esp if applied after some cleaning, etc where you might get some cloudiness.