Not enough skim or flow?

[Jade5051]

I have a standard 75 gallon. Pretty light bioload 2 clowns and a dottyback with a cuc of about 15-20 crabs/snails and a seastar. Tank is pretty mature. Pod population is pretty high.

Currently having some cyano problems.

I only have about 300-350 gph through the tank with two 850 gph wavemakers.

Running a modded AquaC Urchin Pro with a mag5 with a biopellet reactor. I get about 1/4 to 1/3 of a cup of nice wet and dark skimmate a day.

I'm doing a 5 gallon water change weekly to try and correct the problem with a 10 gallon water change monthly. That's a total of 25 gallon water change in a 30 day period.

Should I try to get more flow, skimmate or more water changes? Any advice would be greatly appreciated.

[wildman926]

ChemiClean...It will wipe it out with 0 issues.

[slief]

Chemicals like Chemiclean are a last resort. In most cases, all they do is eliminate the issue for a short time and it will come right back. They are a band aid. Not a solution. Been there done that. What's worse is that many of them also kill the bacterial bed that helps break down waste and that is never a good thing.

As has been mentioned in almost every cyano thread on the forum, flow is one very important factor. Waste tends to settle and break down in the areas with the least amount of flow. Cynao tends to grow in the areas with the least amount of flow where the waste happens to settle. Adding power heads or wavemakers can go a long way to improving flow and keeping waste from settling. Vacuuming your sand or crushed coral and even the rocks is very important in eliminating the waste that feeds the cyano. If you don't vacuum often enough and you don't have enough flow throughout the tank, you most certainly will have cyano issues.

In my system, I use several Tunzes which are controlled by my Apex. I have a profile that kicks in several times a day that stirs things up off the rocks and bottom and suspends them in the water column so that they go into my overflow and are caught by my filter socks. I don't have any detritus issues in my main display nor do I have cyano issues in there. I will also note that my main display is largely bare bottom which also helps in preventing waste and detritus from settling on the bottom where you most often find the cyano. There are a few patches of sand in my tank but not much. The only place I get cyano is in my refugiums where the flow is a fraction of that in my main display. This is also an area that I am not concerned about unlike my main display.

One other thing that I have found to help with cyano is a good UV filter. At one point I had a few patches on some rock in my main display. I noted that my UV bulbs were toast. When I serviced my UV filter and changed the bulbs, the cyano went away within a matter of a week. My UV filter runs on a closed loop in the main display.

[L8Braker]

Dial back your lighting as well by shortening the hours or intensity. Sounds like you may need more flow through the sump as you are only getting 4.6 turnover per hour. Any chance of upgrading that pump for more flow(provided your sump/overflow will handle it). How often do you feed them? Cut back on the feeding as well. Try eliminating them all at once to get rid of it and then slowly add them back. (you probably know alot of this already but just need reassurance). Also throw in some Purigen! That stuff pulls out alot.

[Jade5051]

The cyano is primarily on my rocks so I blasted all the rocks with a pump and then rotated my powerheads to change the water flow in the tank. I'll be doing a water change this weekend. If the problem persist I'll probably upgrade my powerheads and the pump to the HOB refugium because my overflow cannot handle much more. Come to think of it...the problem started about 5-9 days after I added the HOB refugium and the cyano is conveniently located near the output...

[scooter31707]

I would recommend getting some more flow inside the tank. I would push for 10-15x turnover rate.

[Jade5051]

Originally Posted by scooter31707

I would recommend getting some more flow inside the tank. I would push for 10-15x turnover rate.

I'm on the hunt for a 600 gph lifereef overflow. My sump only supports one drain and I would like to push all water through a sock.

[BigCountry74]

i dunno man. it's grown on rocks right in front of direct flow on my tank. me personally i do not think flow affects it - it grows when there is not enough phos filtration regardless of flow. i upgraded to a large and in charge skimmer (rated for 3x my tank lol) and it went away

[Jade5051]

Originally Posted by BigCountry74

i dunno man. it's grown on rocks right in front of direct flow on my tank. me personally i do not think flow affects it - it grows when there is not enough phos filtration regardless of flow. i upgraded to a large and in charge skimmer (rated for 3x my tank lol) and it went away

It kind of is growing on a rock right in front of my powerhead. But, it's also near my refugium output which is only 4 gallons with about 40-60 gph flowing through it. The bioload in the tank is small, 2 clowns a dottyback and a small clean up crew. I have a hard time believing my skimmer cannot handle that. It's also pretty much fish only at the moment just a few corals here and there. I have cut back my feeding. The flow in the tank seems good but I could increase flow through the tank. I'll start there since I know it's an area for improvement. When my bioload increases I'll probably upgrade the skimmer.