Potential flow issue. Need advice.

[Lognor]

Over the past several weeks my Duncan and Frogspawn coral don't seem to be happy.  The duncan has a few heads open, but most are somewhat or completely retracted.  The one's that are open don't have their fingers extended as far as they had been in past.  The frogspawn hasn't been as full/extended either.  All corals are being spot fed every other day (reefroids and Mysis for the duncan).  I've checked my water parameters and everything is in the normal ranges as far as I can tell.

Calcium - 400

Phosphate - 0.5

Nitrate - 0

Salinity - 1.024

My inhabitants are all acting normal.  The other corals seem to be fine. It leads me to think I have a flow issue.  The Duncan and Frogspawn were relatively normal before I added a large rock of zoa and had to change the flow some because the clove polyps looked like they were in a category 5 hurricane.  I changed the direction of one of the powerheads (from front right to front left-middle) and the direction of the pump return (slightly lower on the front glass) and while the cloves are okay now, the others aren't.  Both the frogspawn and duncan are getting flow, but it's less than before, so I thought that would be okay since low to moderate flow seems to be the common recommendation.

 

First pic is what the Duncan looks like most of the time the past few weeks.  Please forgive the nighttime shot, I forgot to get a current one with the day lights on.  After it's under the LED's only, like in the picture, it will become full retracted until the lights come on in the morning.

 

So now, I don't know where to put these stupid circulators to make everyone happy.  The second pic is where they are now and roughly where flow is going.  I have a Hydor 240 and Hydor 425 for powerheads.  All three are bouncing off the front glass.  The second and third pic were taken the day I moved the circulator.  You can see the duncan and frogspawn looked normal at that point.

 

The third pic is a thought I was having based on a lot of other tanks I've seen with similar placement.  I know that placement varies depending on the aquascape and inhabitants.  It's driving me nuts, and I could use some experienced reefers advice.

 

[seabass]

1 hour ago, Lognor said:

I've checked my water parameters and everything is in the normal ranges as far as I can tell.

Calcium - 400

Phosphate - 0.5

Nitrate - 0

Salinity - 1.024

Do you mean phosphate is 0.05 ppm?  0.50 is very high.  I'd also bump the specific gravity to 1.025.

 

How big is this tank?  If flow is a little strong, I might consider removing the Koralia 240.  As far as placement is concerned, you can try some different placements and directions.  You might even try adjusting the flow so that it points just barely up.

 

Then take a string and tie it to the end of a net handle or something, then move the string around the tank to observe the flow patterns and intensity.  Adjust the placement/direction and test it again, keep adjusting until you are satisfied with the flow.

[Lognor]

1 hour ago, seabass said:

Do you mean phosphate is 0.05 ppm?  0.50 is very high.  I'd also bump the specific gravity to 1.025.

 

How big is this tank?  If flow is a little strong, I might consider removing the Koralia 240.  As far as placement is concerned, you can try some different placements and directions.  You might even try adjusting the flow so that it points just barely up.

 

Then take a string and tie it to the end of a net handle or something, then move the string around the tank to observe the flow patterns and intensity.  Adjust the placement/direction and test it again, keep adjusting until you are satisfied with the flow.

For the phosphate, my test kit shows 0.5 which is towards the top of the chart/low end of the scale.  (0, .25, .5, 1, 2, 5, 10).

 

The tank is a Coralife biocube 29.  

 

I can tell i'm getting flow, as I can see the various coral moving.  In the past I actually had much higher flow, but ended up swapping out the power heads for lower gpm units once I started adding all the coral.  Didn't think about the string on a stick though.  I will have to play with that.

 

I'm concerned that the duncan isn't getting enough flow now.  I think it's bouncing around the front of the tank and not getting to the back as much.  I'm wondering if putting the two powerheads in the front pointed at each other would create a better random flow throughout the tank.  I've seen a number of tanks that look the same size with that configuration.  I've only been at this for 6 months, so I still feel clueless about a lot of this stuff.

[seabass]

IME, duncans don't require intense flow.

 

Try moving the powerheads up higher.  It's amazing how much flow is affected by how high the powerheads are.  Play around with it until you are happy.  If you want, you could always replace the Koralia 240 with a 425.

[FISHnChix]

400 ca is on the lower side which makes me think your alk is probally lower too, and low alk will cause this to happen. I would check your alk... 

 

What salt do you use and how often to you do a water change..

[seabass]

4 minutes ago, Weikel said:

400 ca is on the lower side which makes me think your alk is probally lower too, and low alk will cause this to happen. I would check your alk... 

 

What salt do you use and how often to you do a water change..

It also has a little to do with the lower specific gravity.  Everything is a little diluted.

[Lognor]

1 minute ago, Weikel said:

400 ca is on the lower side which makes me think your alk is probally lower too, and low alk will cause this to happen. I would check your alk... 

 

What salt do you use and how often to you do a water change..

I do a 10% water change every week.  I use 1.025 water I get from my LFS.  

 

I noticed one of the numbers from my test is missing, which would be the alkalinity.  If I recall correctly (don't have my log with me) it was 143.  

[FISHnChix]

3 minutes ago, seabass said:

It also has a little to do with the lower specific gravity.  Everything is a little diluted.

Yep 10-4 I didn't notice the salinity... your right the parms are all relative too what the salinity is mixed too

[FISHnChix]

2 minutes ago, Lognor said:

I do a 10% water change every week.  I use 1.025 water I get from my LFS.  

 

I noticed one of the numbers from my test is missing, which would be the alkalinity.  If I recall correctly (don't have my log with me) it was 143.  

Hmm maybe check your log.. 143 doesn't seem right although I don't know what unit of measurement you are using most of us use dkh which is a normal range of 8.0 - 11.0

[Lognor]

1 minute ago, Weikel said:

Hmm maybe check your log.. 143 doesn't seem right although I don't know what unit of measurement you are using most of us use dkh which is a normal range of 8.0 - 11.0

Ok, that makes sense.  A couple of weeks ago, I got a bad batch of salt water and due to my own mistake of not checking it before I used it, I put in low salinty water on water change and dropped the salinity to 1.021-1.022.  I had brought it back up to 1.024-1.025 within a week, so I thought I was ok.  Checking yesterday I was at 1.024 again, so I need to bring it back up again.  Yeah, I'll check my charts and logs tonight to confirm which numbers we're talking about.  I know that I had checked them against the expected norms and everything seemed to be in range.

 

I really really appreciate the feedback.  I'll work on bringing the salinity up some more and adjust the powerheads a little.

[Clown79]

143ppm alk is 7.9 dkh - it's fine

 

Even ca at 400 is fine

 

Them staying stable is an important factor 

 

You use sw water at 1.025 but you said sg is at 1.024- are you topping up too much freshwater because salinity swings could be an issue.

 

Euphyllia and Duncan's don't like high flow and retract when flow is too direct or too much.

 

Unplug the hydor 240 and see how they react - it will take a few days to know. 

 

Another cause is alk fluctuations 

[Lognor]

14 hours ago, Clown79 said:

143ppm alk is 7.9 dkh - it's fine

 

Even ca at 400 is fine

 

Them staying stable is an important factor 

 

You use sw water at 1.025 but you said sg is at 1.024- are you topping up too much freshwater because salinity swings could be an issue.

 

Euphyllia and Duncan's don't like high flow and retract when flow is too direct or too much.

 

Unplug the hydor 240 and see how they react - it will take a few days to know. 

 

Another cause is alk fluctuations 

Thanks for the feedback.  I've been using 1.025 normally yes.  Not sure why it's back down to 1.024.  I rarely have to top off during the week since it's an enclosed unit.  When I do my water change I fill to just above the max fill line (which I know is a mostly arbitrary measure for these tanks.  The only time I use something other than salt is for feeding.  I use RODI when feeding.  I don't alkalinity in my test kit, so I will get a test kit for it so I can check that.