New Algae Scrubber newbie

From the pic, if you are referring to the "T" as the "left channel" and the elbow as the "right channel", and water input is on the left side of the T, I would think the right channel would get more flow. The dynamics of water flow in that setup would be like this: the water comes into one end of the T, and then it has 2 paths: one (left) takes a sharp 90 degree turn through a tap outlet (the tee) on the side of the flow path, the other (right) goes straight through the other end of the T and then into a 90 elbow, which is more of a "sweep" turn. While it's true that the elbow induces a form of head-loss, I would expect that path to be the one of least resistance actually.

But that's just the on-paper engineer in me. If I built and tested it, that could be wrong.

 

Red growth like that does occur as the scrubber matures, nothing "wrong" with it, if it's turf-like you can scrape it off and it will come back, but slower than GHA.

If it's more slimy, this happens also from time to time depending on your tank dynamics, usually that just rinses away and will come and go, usually just a phase of growth.

I wouldn't let it grow that long (length of time) without some kind of harvesting. 18 days is typically my limit. You'll get a shading effect and the underlying layers of algae will not be growing. Think of it like an old tree vs new tree. An old tree doesn't uptake nearly as much CO2 as a new tree.

Also allowing it to go that long give the red algae time to grow in. Again, that's not the worst thing but GHA seems to grow faster.

Still don't know what to tell you on the flow, I think I need some kind of drawing to figure out what might be going on. I doubt there is a blockage but I suppose that's a possibility.

The bottom line always remains: how is your tank doing? If it's doing well, then it's less of a concern

 

I missed this last message!!

Has anything changed/improved in the last few weeks?

 

Do you run any activate carbon? If not, you might add a small amount. There might be some chemical interactions going on that could be causing STN

 

As long as your algae growth is good and nutrients are under control, I would leave it

Lighting becomes more and more important as you start to house more complex and sensitive corals. You can get away with black box fixtures on softie tanks and maybe some LPS, but some corals don't like cheap lights. At least that's what I've seen/read...

 

I can't claim to be an expert on coral, and especially not SPS. Water chemistry, system biotype, coral chemical warefare (between other SPS and between SPS and soft/LPS, etc), placement (light intensity, water flow, etc)...many many things come into play with SPS and it's not usually "just one thing".

What I do know, based on anecdotal gathering of the experience of others, is that SPS on a tank with a scrubber seem to do better when you have some level of skimming (even undersized) and/or use of carbon.

The rest of the details on placement, lighting, water chemistry, etc...I'll leave those to others.

 

Activated carbon

physical proximity of other corals is absolutely important. But so is chemical interaction.

Bob Fenner spoke at one of our fests a couple years ago, one of his topics was chemical warfare. One of the things he talked about was the "chemical soup" that forms in systems. Over time corals will adapt to each other chemically, usually after some warfare and interaction. One of the ways that he recommended to acclimate corals to each other was something that you don't hear much about. He recommended a sort of quarantine method (not a full QT like you do for fish) that involved holding the new corals in a separate tank, and then performing water exchanges between the 2 tanks so that each coral was exposed to the other coral(s) in a passive manner. The idea being that if you place water from tank A into tank B, the corals in tank B will get chemically exposed to the corals in tank A without causing a full-blown cascading war of chemicals. Corals in tank A will react to the chemical presence of the tank B corals, but there will be no counter-reaction by the tank B corals because they're not in the same system. After a period of time, you can connect the 2 systems as a sort of second-stage (constant exposure) or increase the exchange frequency, and then finally put them in the tank together. By that time, both "parties" have cooled their jets. Something along those lines. This is probably more important in systems with low amounts of PWCs (which is more prominent in tanks running scrubbers).

The same applies to fish, but to a lesser extent (chemically at least) I believe.

When it comes to physical proximity, during the day it might not seem like corals are too close to each other. But at night, some corals will extend sweeper tentacles or extend out more than during the day, and this is when the damage can occur - both physically and chemically. That's why knowing your corals and knowing the correct placement and distance is so important. If you've seen evidence of stinging, that's a big sign that your coral placement needs to be adjusted.

That's largely the extent of my rather basic understanding on thees couple items...activated carbon can take the edge off the chemical warfare. Usually, the inter-coral chemical warfare will fade over time.

The other reason to use activated carbon in a scrubber-SPS tank is due to the chemical allelopathy effects of algae. Similar to chemical warfare between corals, algae will also engage in chemical warfare against other algaes. It's not just out-competition for nutrients that causes tank algae to die off and scrubber algae to thrive. Largely, the "ideal conditions" situation is what leads to algae preferentially populating the scrubber versus the display tank, but there is (in my opinion) still a chemical aspect at play also. Activated carbon can also mute this effect in the same manner as it does with coral chemical warfare.

I don't think anyone has solid answers on the exact mechanisms, that's probably largely in part to the diversity from one tank to the other. It's difficult to apply blanket advice and give blanket answers so many things. It also makes diagnosing issues very difficult at times

Hope this all helps...kind of a "brain dump"