How soon can I start dosing?

[BioReefed]

I have a 16 gallon Biocube with a few corals and no fish for now since my tank is going fallow after my fish died of brooklynella. Recently battling cyano, and it seems it's going away slowly. My tank is a little over three moths old, and as you can see I didn't have a good start.

My tank is looking better now even though the cyano still there. 

But I have noticed that my parameters are not consistent. I'm performing water changes every two weeks and my alkalinity doesn't go up, it is at 6 right now. Also my calcium stays at 360 constant, my PH stays at 7.8, My Nitrates and Phosphates keep going to zero and I have to add some NeoNitro and NeoPhos to keep it at 5 and 0.2, and I don't have any media in the chambers to lower those parameters.

And I was wondering if, at only three months old, do I need to start dosing some calcium and alkalinity? I heard of a product called All for Reef, but it says that you should use it after your tank is 12 months old. What can I do to elevate the calcium, alkalinity, and PH on my tank? 

Here is a picture of my tank.

 

[Tired]

If minerals or nutrients that your corals need are too low, you should consider dosing those minerals or nutrients. If they aren't too low, don't dose. It's nothing to do with age, only with what your tank needs. Tank needs minerals? Add minerals!

 

What fish do you have? If you're fishless like you appear to be, that would explain your nutrient problem; your corals are using it all up and there's no fish waste to replace it. You might want to consider adding a fish, and you might also want to aim for higher numbers when you dose- 5ppm nitrate is about bare minimum for a soft coral tank, and 0.02ppm phosphate (assuming that's what you meant) is too low. 

[BioReefed]

11 minutes ago, Tired said:

If minerals or nutrients that your corals need are too low, you should consider dosing those minerals or nutrients. If they aren't too low, don't dose. It's nothing to do with age, only with what your tank needs. Tank needs minerals? Add minerals!

 

What fish do you have? If you're fishless like you appear to be, that would explain your nutrient problem; your corals are using it all up and there's no fish waste to replace it. You might want to consider adding a fish, and you might also want to aim for higher numbers when you dose- 5ppm nitrate is about bare minimum for a soft coral tank, and 0.02ppm phosphate (assuming that's what you meant) is too low. 

Hmm, I guess I need to bump that dose of Nitrates and Phosphates up. What about alkalinity and Calcium? alkalinity is 6 and calcium 360.

As of right now I started a QT a couple of days ago and I have 2 Mai Tai Clownfish there, waiting to be introduce in the main tank

[MrP]

You can use AFR at any time. You will need to elevate your calcium, alkalinity, and magnesium to your desired levels prior to starting AFR. It is meant to keep them stable, not elevate them. Start slow as you want to give the bacteria that utilize the calcium formate in AFR time to process it into alkalinity. 

[BioReefed]

2 hours ago, MrP said:

You can use AFR at any time. You will need to elevate your calcium, alkalinity, and magnesium to your desired levels prior to starting AFR. It is meant to keep them stable, not elevate them. Start slow as you want to give the bacteria that utilize the calcium formate in AFR time to process it into alkalinity. 

thank you.

Any suggestions on what to use to elevate calcium, alkalinity and magnesium? 

[MrP]

6 hours ago, BioReefed said:

thank you.

Any suggestions on what to use to elevate calcium, alkalinity and magnesium? 

For alkalinity, add approximately 4 1/2 tablespoons of baking soda to 16 oz. of water. You can then use the BRS alkalinity dosing calculator. https://www.bulkreefsupply.com/reef-calculator/alkalinity-calculator-reef

 

Brightwell Reef Code A for calcium and Brightwell Magnesion for magnesium. These are both concentrated and they are also on the BRS dosing calculator. All calcium and magnesium supplements on the market will get the job done. It just comes down to brand preference. I personally use BRS calcium chloride and their magnesium mix and just mix up a gallon of them but not everyone needs a gallon on hand, I sure don't but it's there if I need it. 

[mcarroll]

21 hours ago, BioReefed said:

My tank is a little over three moths old, and as you can see I didn't have a good start.

Going a little slower and avoiding some things until later could have helped, BTW.  Having this much "experience" at three months means you were moving a bit too fast.  Rushing things yields somewhat predictable results that you've been discovering.  As the old saying goes:  Nothing Good Happens Fast In A Reef Tank  👍

 

If you haven't gotten a good book on reefing yet, I'd highly recommend one.  Martin Moe is a great author and who I'd suggest starting with, but there are tons of great options.

 

21 hours ago, BioReefed said:

But I have noticed that my parameters are not consistent. I'm performing water changes every two weeks and my alkalinity doesn't go up, it is at 6 right now. Also my calcium stays at 360 constant, my PH stays at 7.8, My Nitrates and Phosphates keep going to zero and I have to add some NeoNitro and NeoPhos to keep it at 5 and 0.2, and I don't have any media in the chambers to lower those parameters.

Your tests for Ca and Alk aren't equally sensitive, for one thing.  

 

For another, there're orders of magnitude more Ca in the water as compared with alkalinity.  In one of Randy Holmes Farley's articles, he makes the point that even if 100% of the alkalinity combined with Ca and precipitated out of the water as chalk, Ca would only drop by 20 ppm or some small number.   The point being in your case, that you'll notice alkalinity changes WAY SOONER than you can notice calcium changes.

 

Don't worry about pH any more.   Knowing the pH can be interesting sometimes, but your pH level is directly related to the alkalinity level...which you are already testing and which is actually significant to the tank's inhabitants.  (If you weren't already monitoring/maintaining alk, then pH could be a little more useful to watch.)

 

Please test alk, Ca and Mg on a freshly mixed batch of saltwater and see what parameters you get.  It may explain why your alk isn't moving.

 

It's also possible that your corals, algae and nitrifying bacteria are just using A LOT of alk.  Water changes every two weeks isn't going to add very much to alk if there's significant demand.  Increasing the quantity and/or frequency of water changes may help BUT only consider this AFTER you test your new saltwater per the comment above.

 

If everything else checks out, then it could just be time for regular dosing.

 

21 hours ago, BioReefed said:

What can I do to elevate the calcium, alkalinity, and PH on my tank?

If it turns out to be the case that you just need to start dosing (but not for pH!), I'd consider ESV's two-part system as it is easy and it is tried-and-true for results.  

 

Other brands work too, but IMO ESV seems to have the best, most balanced, formula.....magnesium and trace elements are included in the two basic parts, for example, whereas almost all other "two parts" are actually three parts.  Whatever you choose, make sure you read the directions and follow standard protocol for testing and dosing.  

 

BTW, if you choose a one-part system (eg All For Reef), I would stick with Brightwell's products or Tropic Marin's Bio-Calcium.  (<-not just calcium).   ESV is a better option than one-part IMO, but you can't deny that one part is simpler!  

 

Personally, I used Brightwell Elements (and Liquid Reef) and Bio-calcium before I switched to two-part (ESV and Brightwell) and finally, for budget reasons, to DIY two-part Recipe #2.  (I don't recommend DIY when you're starting out even though it's cheap.)  🙂

 

 

21 hours ago, BioReefed said:

Here is a picture of my tank.

I don't see any cyano.   But I do see some nice spots of coralline!  👍

 

Are the bottom rocks painted/dyed, or are they THAT LOADED with coralline algae??

[mcarroll]

...posted too quick and missed a couple replies.

 

18 hours ago, MrP said:

You can use AFR at any time. You will need to elevate your calcium, alkalinity, and magnesium to your desired levels prior to starting AFR. It is meant to keep them stable, not elevate them. Start slow as you want to give the bacteria that utilize the calcium formate in AFR time to process it into alkalinity. 

Hypothetically yes, but they advise not in the first 12 months for a good (ecological) reason.   Staying away (and using one of their other products) is sound advice for anyone getting started.

 

16 hours ago, BioReefed said:

thank you.

Any suggestions on what to use to elevate calcium, alkalinity and magnesium? 

At this point it seems like you could use some free reading!   "Reef Aquarium Water Parameters" by Rand Holmes-Farley is a nice starting point, with links to more specific topics like alk and ca.   Read everything you can find on alkalinity.   Randy is a great author to search for on these things.  But also Dr Craig Bingman.   Also, if you don't have a good book on the topic, check out Martin Moe's books.  Classics!!  (And updated.)

 

Baking soda, calcium chloride and magnesium sulfate (epsom salts) are the DIY ingredients, but Brightwell, ESV and others make premixed solutions for this purpose if you'd prefer. (Not the same as the two-part formulas.  Don't use the two-part components to make one-time adjustments to your water.)

 

The Reef Chemistry Calculator will help you compute mixtures for stock solutions (if you choose DIY) and it will help you calculate dosage amounts.

 

Does your LFS carry any of these brands?

[BioReefed]

2 hours ago, mcarroll said:

ESV is a better option than one-part IMO, but you can't deny that one part is simpler!  

Thank you!.

I know I need to slow down, it is really hard, but I'm trying to take my time and make it work. I did got the ESV component #1 and #2 for alkalinity and calcium, and the more I read the instructions the more I don't understand. Everything in this hobby seems to contradict itself. I used the online calculator to figure out the right amount to add in my tank. If I look to rise my alkalinity to 8 for example, I get this: 

Total system value : 16 gallons

Current alkalinity level: 6

Desires alkalinity levels :8

amount to dose :  21.43 ml

 And it tells me to add the same amount for the calcium. But my calcium it is low as well and if I add that same amount of 21.43ml, my calcium is not going to go up.

And if I use the calcium calculator it gives me a different amount to dose and if I use that same amount for the alkalinity it will go way up, right?

The calcium calculator tells me:

Current Calcium level :360

Desired Calcium levels: 400

Amount to dose: 61.41 ml

So I don't get how do I have to dose the same for both parameter if each one gives me a different dose to add. Do I add 61.41 ml for both parameters just to raise my calcium? or the alkalinity dose of 21.43 both ways to just raise the alkalinity?

And on the bottle says to only add 1 ml per 4 gallons per day only, so for my tank I can only add 4 ml, but the calculator tells me to add 61.41 ml so 😑. I have no idea what to do, I know the amount but I can't add it because it is too much for a day? This seems very complicated.

[mitten_reef]

it is possible that you may need that much to bring up the levels to desired level.

 

once you reach your desired level, then your daily dose has to be re-calculated based on how the tank consumed Alk and cal daily.

 

Your system volume is not 16 gallon, it should be estimated of the actual water volume, subtract rock and sand. and not based on the tank dimension, because they tend to list it as if your filling the tank to the rim, which you probably don't, plus all the not-fully-filled chambers in the back compartments.

 

[BioReefed]

3 hours ago, mcarroll said:

On 3/20/2023 at 2:33 PM, BioReefed said:

 

I don't see any cyano.   But I do see some nice spots of coralline!  👍

 

Are the bottom rocks painted/dyed, or are they THAT LOADED with coralline algae??

The cyano it is mostly hanging on my gorgonians, it is really annoying. I blow it every day with a turkey baster and they come back every day. Really long strings that get longer and longer if I don't remove them. And the bottom rock it is loaded with coralline, I'm not sure why only that rock got covered like that, the other ones only have a few spots

[BioReefed]

1 minute ago, mitten_reef said:

it is possible that you may need that much to bring up the levels to desired level.

 

once you reach your desired level, then your daily dose has to be re-calculated based on how the tank consumed Alk and cal daily.

 

Your system volume is not 16 gallon, it should be estimated of the actual water volume, subtract rock and sand. and not based on the tank dimension, because they tend to list it as if your filling the tank to the rim, which you probably don't, plus all the not-fully-filled chambers in the back compartments.

 

I didn't think about that. That's a good point.

But should I add that much amount of liquid? 61ml? even though it says to add only 4ml per day?

[mitten_reef]

4 hours ago, BioReefed said:

I didn't think about that. That's a good point.

But should I add that much amount of liquid? 61ml? even though it says to add only 4ml per day?

First, recalculate assuming some volume loss due to space taken up by sandbed, rocks and empty filtration chambers. Id guess that tank has around 13 gallon of water volume. 
 

when it comes to dosing, if you don’t know what to do, start at half or quarter of recommendations, see how it goes. You can always dose a little more the following day(s).  
you can’t really take back if you overdose something. By the time you notice it, you’ll need some serious emergency water change. Don’t ask me how I know that, haha. 

[mcarroll]

On 3/21/2023 at 4:45 PM, BioReefed said:

Thank you!.

I know I need to slow down, it is really hard, but I'm trying to take my time and make it work. I did got the ESV component #1 and #2 for alkalinity and calcium, and the more I read the instructions the more I don't understand. Everything in this hobby seems to contradict itself. I used the online calculator to figure out the right amount to add in my tank. If I look to rise my alkalinity to 8 for example, I get this: 

Total system value : 16 gallons

Current alkalinity level: 6

Desires alkalinity levels :8

amount to dose :  21.43 ml

 And it tells me to add the same amount for the calcium. But my calcium it is low as well and if I add that same amount of 21.43ml, my calcium is not going to go up.

And if I use the calcium calculator it gives me a different amount to dose and if I use that same amount for the alkalinity it will go way up, right?

The calcium calculator tells me:

Current Calcium level :360

Desired Calcium levels: 400

Amount to dose: 61.41 ml

So I don't get how do I have to dose the same for both parameter if each one gives me a different dose to add. Do I add 61.41 ml for both parameters just to raise my calcium? or the alkalinity dose of 21.43 both ways to just raise the alkalinity?

And on the bottle says to only add 1 ml per 4 gallons per day only, so for my tank I can only add 4 ml, but the calculator tells me to add 61.41 ml so 😑. I have no idea what to do, I know the amount but I can't add it because it is too much for a day? This seems very complicated.

You are on the right track....and I could have been more clear earlier...

 

First, so you see what I'm doing, here is what the Reef Chemistry Calculator says if I assume your tank is holding 13 gallons of water...and I adjust your Ca target to 420 ppm:

 

There are separate (generally cheaper) products for the purposes of making your initial chemistry corrections.

 

For example:

After you use those products to set your target Mg, Ca and alk levels THEN you use the two-part system...

...to maintain your target levels levels.

 

Dial up Mg to around 1300-1400 ppm.  

Set calcium at 420 ppm.  

Set alkalinity to no less than 8 dKH so you have a little extra time before levels get "too low".

 

If you didn't mind "wasting a little" of your two-part then you can go ahead and use your two-part to make the adjustments and not worry about the other chemicals.  But then you end up with uneven amounts of part1 and part2 and have a little bit of "waste" at the end of the bottles.  You can decide how big a deal that is.

 

BTW, there can be instances where alk will be used more than the 1:1 ratio with calcium since LOTS of biological processes use alk – not just hard coral growth.   Use the three simpler products above anytime one-off corrections like this are needed.  👍

 

Last thing for now:  I know it can be a lot of information to digest all at once (I read and re-read all this info more than once before I got started back in the day.) but that link I gave you is an excellent "umbrella" article for water chemistry and dosing, with links to just about all related topics.  So take your time and get through it as best you can!  🙂  

 

....and don't forget to test Ca, Mg and alkalinity in your newly made seawater that you're using in your water changes.  If that is the cause of your chemistry issues, then you need some additional advice!

[BioReefed]

1 hour ago, mcarroll said:

for the purposes of making your initial chemistry corrections

Wow, I really appreciate all that information. So just to be clear. In that chart you sent me, I'm looking to raise the calcium to 420 so I need 48.7 ml of the calcium bottle, but since I can't use all at once, or is not recommended. I need to add only 1/3 of those 48.7, so 16.2 the first day, 16.2 the second day and 16.2 the third day? 

And in the bottom says balanced alkalinity, does that mean I need to add that amount (2,95 meq/l)? or I add the other amount of the product required for alkalinity of 12.5 ml? Not completely clear if I have to add the calcium first, and then after a few days when the levels are where I want them, start dosing alkalinity? or I have to add both at the same time.

Sorry for asking too much, I just want to make sure I do this correctly.

Thanks again @mcarroll

[mcarroll]

READ

THAT 

ARTICLE

🙂

 

...and read on...

 

8 hours ago, BioReefed said:

Wow, I really appreciate all that information. So just to be clear. In that chart you sent me, I'm looking to raise the calcium to 420 so I need 48.7 ml of the calcium bottle, but since I can't use all at once, or is not recommended. I need to add only 1/3 of those 48.7, so 16.2 the first day, 16.2 the second day and 16.2 the third day? 

Yes.  Those instructions are VERY conservative.  The object behind the instruction is to avoid creating a precipitation event.  (Seawater is a supersaturated solution.  If you don't know about that.....ya, read that article ASAP!  I'm serious, it's GOOD.)

 

8 hours ago, BioReefed said:

And in the bottom says balanced alkalinity, does that mean I need to add that amount (2,95 meq/l)?

No.   Balanced alkalinity is a comment regarding the supersaturation I just mentioned.  

 

8 hours ago, BioReefed said:

or I add the other amount of the product required for alkalinity of 12.5 ml?

Yes.  🙂 

 

8 hours ago, BioReefed said:

Not completely clear if I have to add the calcium first, and then after a few days when the levels are where I want them, start dosing alkalinity? or I have to add both at the same time.

They should be added in such a way that they cannot combine before they can dissolve into the water.  (They WANT TO combine and precipitate out.  READ THAT ARTICLE.)

 

8 hours ago, BioReefed said:

Sorry for asking too much, I just want to make sure I do this correctly.

Thanks again @mcarroll

No problem – there's a lot to learn at this stage of things!!!! 

[BioReefed]

5 hours ago, mcarroll said:

No problem – there's a lot to learn at this stage of things!!!! 

Once again, thank you very much. I will read the article now.

[BioReefed]

On 3/23/2023 at 3:18 AM, mcarroll said:

READ

THAT 

ARTICLE

The article was very helpful and I learned a lot form it. But still got me a little confused, like I said before, everything seems to contradict itself. Specially talking about Nitrates and Phosphates, if at zero it is a problem, but if they are elevated, also a problem.

Anyways, I think I manage to raise my Calcium and alkalinity, it was a little challenging. The calcium went up fine but the alkalinity didn't. I kept dosing until I got calcium to 400 and alkalinity at 8. Now I need to figure out when to use the All for reef and how much to use. I will test next weekend after the water change and then daily to see how much the corals are using. Should I get a single dosing pump for the A4R liquid? 

Also  I updated my wavemaker for another one, the flow is stronger but different, and I keep seeing that cyano growing again in the sand, it has never been gone completely, always covering my gorgonians, I really don't want to use chemicals to get rid of it. Does that ever goes away, or there's some cyano always present in the tank.

 

 

[Tired]

Think of it this way. If you drink no water over the course of your day, you'll have a big problem. If you drink 3 gallons of water a day, you will also have a big problem. It's not a contradiction to say "you should drink some water, but not a huge amount", and the same thing applies to nitrates and phosphates. Corals need a moderate amount of nutrients to thrive. 

 

Cyano will always be present in microscopic amounts, but a stable, mature tank should have little to none of it actually visible.

[BioReefed]

10 hours ago, Tired said:

mature tank should have little to none of it actually visible

I thought it was going away, but today I came home and the glass is foggy covered all in red cyano. I hate that thing. I will keep try to get rid of it without using the chemicals. I saw a video of a guy who said he got rid of it by doing weekly water changes. I'm doing by weekly maybe I should do it every week IDK

[Tired]

Weekly water changes will only help cyano if your problem is that your nutrients are too high or you have dissolved organics that need to be removed. If you have cyano because your tank is immature, water changes won't help. If you have cyano because your nutrients are too low or because your water change water is high in organics, water changes will make it worse. 

[fenderchamp]

I wouldn't let myself get to worked up.  before you add anything, compare you water to newly mixed water, before you add it to the tank. Then compare your water after you do the water change.  that should give you a rough idea of 1. what state your water is in compared to new water, 2. how much it's changing in the course of a water change.  If you're alkalinity is pretty low after the water change compared to the newly mixed water, up your water change volume a bit next time, or do a few more frequent water changes to get it up to snuff.  if you can see that the water in the tank before and after the water change indicates that the tank is using a lot of alkalinity, then consider using a supplement, and probably increasing your water change volume and or frequency.

 

I've been using 2 little fishies Cbalance with some success for a while.

 

I think your tank looks pretty good, if you go nuts on it, it probably won't. 

 

 

 

 

 

[BioReefed]

10 hours ago, Tired said:

Weekly water changes will only help cyano if your problem is that your nutrients are too high or you have dissolved organics that need to be removed. If you have cyano because your tank is immature, water changes won't help. If you have cyano because your nutrients are too low or because your water change water is high in organics, water changes will make it worse. 

I should have gotten a Hamster instead lol

[Tired]

Hamsters need much larger enclosures with much deeper substrate than the pet store tells ya, so they're not necessarily that much easier. Though at least they do tend to be low on algae!

 

In all seriousness, if you want the easiest pet in the world, you want opae ula shrimp. Set up a brackish water tank in the 5-gallon range, let it sit empty until algae starts growing, then add shrimp. Top off with distilled or RODI water once a week, provide with indirect light, feed the tiniest pinch of food once a month (or not at all if dead bugs fall in sometimes), and they will thrive, grow, and breed. No equipment needed bar a light, and you can skip that if you can put the tank in indirect window sunlight. You actually want algae for these guys- they eat it! The main downside is that they're tiny, half an inch long, so they're hard to enjoy without putting your face right by the tank.

[mcarroll]

On 3/28/2023 at 9:47 AM, BioReefed said:

but if they are elevated, also a problem.

That's in the wild where the entire situation is more complicated.  Temperature flux is also crucial....but who's going to keep their reef at ≤69ºF for a month, temporarily?  We haven't found any volunteers SO FAR. 😉 

 

In our tanks, where things are relatively simple, only one scenario really seems to provokes a dino bloom with significant likelihood and frequency.  Nutrients bottoming out to 0.0 ppm is part of that scenario.  

 

On the other hand, reef tank dino blooms that seem to be triggered by high nutrients (or something else besides low nutrients) are almost unheard of, but they do happen.  From the few examples I've bumped in to, those blooms don't seem persistent...usually clearing up on their own.  They also seem to happen on mature systems, not brand new systems.  

 

Quite different.  Not enough examples to really draw any conclusions on those types of blooms IMO. 🤷‍♂️

 

In a home reef, we really don't have much to worry about from "too much" nutrients.  "Too much" is a relative term, even in the wild.  At home we have control over almost everything, so effects aren't the same.  We can almost just look at nutrients as nutrients.  Literal interpretation, no ulterior motive or purpose. 😉  Especially at the tank's beginning when demand for nutrients can pretty easily outstrip supply.   Also, some of the very best and very longest-lived hard coral reef tanks have had astronomically high nutrient levels.

 

Did you pick up ESV BIOINC as well as Tropic Marin AFR?  I'd consider trading the AFR for some more ESV.   You don't need "pro-biotic dosing".   I think I heard that Tropic Marin doesn't actually recommend that for tanks under 1 year old anyway.  I agree, although I don't see that caveat mentioned on their website.  

 

In any event, Tropic Marin (and others) makes other "all in one" dosing solutions, if that's the main aspect of AFR you were after.  

 

For example, Tropic Marin Bio Calcium, which is neat since it is dosed in powder form.  Also, TM has Carbo Calcium if you prefer to have a liquid product.  The main difference between those two and AFR is the lack of Mg.  Mg gets used at a VERY low rate though, so really not a big deal...not an issue at all on a new tank.  But this is also why TM sells Bio-Magnesium (which also supplies potassium).  All are super-easy to use.  I've used Bio-calcium personally...in my case, water changes with Reef Crystals was enough to maintain magnesium levels.   I switched to ESV and other systems due to expense once demand got higher though.

 

On 3/28/2023 at 9:47 AM, BioReefed said:

Also  I updated my wavemaker for another one, the flow is stronger but different, and I keep seeing that cyano growing again in the sand, it has never been gone completely, always covering my gorgonians, I really don't want to use chemicals to get rid of it. Does that ever goes away, or there's some cyano always present in the tank.

Cyanobacteria can re-infect the system from the dust in the air, so treatment is really not recommended under most circumstances.

 

Make sure your skimmer is cleaned regularly – daily is ideal; along with wet skimming as much as possible.  Make sure no other filters are running dirty for more than a few hours either.  (This really recommends against mechanical filtration in general....mechanical filters will need to be monitored constantly.)

 

Make sure you are using RODI that's 0 TDS as your base water.  If your filters are old, replace them.  (If your water is from the LFS, question them on these things.)

 

Are you feeding or dosing anything for the gorgonians?

 

Take care of any other factors before this one....but, IMO if cyano is covering your gorgonians, that could be a sign that your gorgonians aren't that happy to begin with – stressed.   The story could be a little different for Gorgonians than other corals, but in general most corals create excess mucus when they are stressed.  I suspect this is helpful to them under natural flow conditions in the wild, but under tank conditions I think cyano benefit from the organics included among the "excess" mucus.  (Mucus is, among its many roles, a base for delivery of things like waste, immunity factors, etc.). Certainly if there's any slow die-off happening, you can expect that to attract cyano.

 

Let us know how the change in flow is once you've had a chance to experiment.   Use some flake food and or other 'tools' to 'measure' your flow after you make changes.  Obviously watch coral behavior as well, but you need something to emulate food particles and detritus....flake food is pretty excellent at that.  Something like PurpleUp that clouds the water in a non-bad way could be useful for visualizing flow as well.