Algae/sand advice

[beglitis]

Hello everybody,

I am looking for some advice regarding my tank. It has been up an running for a few months now without any major issues (touch wood). I have added quite a few gadgets to make the system a bit more robust. I am constantly concerned about the amount of algae I get on the sand hence why I am reaching out. The tank is a Nuvo 24, I also have a small CPR AquaFuge (which is around 2 gallons) and a AFM Marine (or AquaMaxx) HOB 1 skimmer. I also have an IM desktop media reactor with RowaPhos and Purigen/Carbon in the media baskets. On the top shelf of the baskets I have polyfilter underneath some generic filter floss that captures the big free floating items. Lighting is 2 x Kessil A360W for the tank and a Kessil Amazon Sun for the refugium (total overkill but it was a bargain purchase from eBay). For flow I have 2 x Vortech MP10W and the IM spin streams. The system is controlled by the Neptune Apex. I wanted to start small and on a budget but you can guess things went out of control a bit and retrospectively I wished I had gone for a bigger tank. Top off is done via a Tunze Osmolator and I have an RO/DI unit for filtering the tap water.

This is what the tank used to look like a few months ago

I am guilty of overstocking the tank. The fish are

1 x oscellaris clown fish
1 x midas blenny
1 x banghai cardinal
1 x orchid dottyback
1 x yellow watchman goby
1 x wrasse of unknown origin whatsoever
1 x scooter blenny (dragonet)
1 x cleaner shrimp
2 x peppermint shrimp
1 x fire shrimp

Things seem to be OK because every fish has its own area in the tank. The cardinal just floats in low flow areas, the clown swims around and about, the blenny mostly stays inside a hole on a rock, goby usually sticks on the sand in a favourite spot of his, dottyback hides inside the rocks and the wrasse seems to prefer swimming in the water column. This particular wrasse is extremely docile but it is quite big and inevitably I feel more suited to bigger tanks so although it seems happy it is on its way out if I manage to catch it. I also have an assortment of snails, bumble bees, nassarius, trochus, hermits. Due to the heavy load, I added the CPR refugium to give a bit more water volume to the system. Inside it I have some live rock and chaeto et al. The massively uprated skimmer is for cleaning after the waste. I did do quite well with the Tunze 9001 (very nice) but I decided to upgrade a couple of days ago and I have been running the AquaMaxx/AFM Marine skimmer since then.

After some re-arrangement of the left island of rocks plus another layer of rocks on top of it, the tank now looks like

The MP10s are controlled by the Apex and they iterate over various modes during the day, mostly reef crest up to 60% with nutrient transport up to 60% after feeding. Nighttime is a constant 5%.

My problem is that although I am quite disciplined with water changes (a bucket of 10-13L every week) I seem to get algae on the sand. You can see the algae between the glass and the sand in the pictures but I also get some green tint on the rocks (not hair algae though) and carpet like algae on the sand surface.

Apart from overstocking (with the wrasse out as soon as I manage to catch it) is there something else I should look into regarding the algae and the sand in general? My sand looks rather sorry. The MP10 should be keep the detrius suspended but I also stir the surface every now and then (just the surface). What do you recommend? Should I just ride it out with frequent water changes? Is this algae part of a bigger cycle given that the tank is relatively new?

Any suggestions that pop in your minds by looking at the photos would be hugely appreciated!

PS. The left island is due to re-arrangement again. I liked the idea of having even more caves but it doesn't look as nice so the top two rocks will go into the refugium and/or returned to the LFS. This Fiji live rock though is really nice and I am sure I wouldn't be as lucky without it filtration-wise.

 

[beglitis]

By the way, just in case more people think about HOB equipment (refugiums, skimmers etc), both of them in my case actually sit in boxes wrapped up with black duck tape to make them "invisible" and more solid. They do not put any pressure on the tank's walls.

 

[beglitis]

Shameless bump

 

[CStrickland]

are you cleaning the sand with a vacuum when you change your water?

Are you doing something to make sure the dragonet gets enough to eat?

 

[beglitis]

are you cleaning the sand with a vacuum when you change your water?

Are you doing something to make sure the dragonet gets enough to eat?

I have a vacuum tube that sucks water in that I use during water changes but it also sucks in the sand, not just the detrius. What I have been doing lately is to disturb the top of the sand so that the detrius gets suspended in the water column and then filtered out by the socks or the skimmer.

Regarding the dragonet it will go after brine shrimp but I also have a bi-weekly subscription to copepods that I put in the refugium and then display tank. I have it for a few months now and it seems ok but I need to do more on that front.

 

[CStrickland]

idk, the way your powerheads are up at the top, seems like the stuff that was heavy enough to fall in the first place would have a good chance of just sinking back down again, rather than shooting up into the overflow, y'know? Maybe practice pinching the tube so the suction is slow enough that the sand falls back out. For me, the gadgets are a poor substitute for husbandry, but not everyone vacs their sand so meh.

The thing is, you've got a lot of fish - that's a lot of food and poo. Understocked tanks seem to have it easier when it comes to balancing nutrient export and import. Overstocking makes more work. Sometimes gadgets are a lot of work too, you're cleaning out all those pads and filters and socks a couple times a week right?

All the coralline and no algae makes me think your water and rocks are pretty clean, even though you don't list any parameters. So I think the flow has kept everything from the sand up clean and pretty. But your sand got dirty as fish poop and old food landed on it. The water down there got a lot of nutrients in it as those things have decayed, and from sitting in it, the sand itself has absorbed some too. Now those nutrients are fertilizing algae and cyanobacter. None of the reactors and fuges and skimmers can clean water that doesn't reach them.

 

[beglitis]

idk, the way your powerheads are up at the top, seems like the stuff that was heavy enough to fall in the first place would have a good chance of just sinking back down again, rather than shooting up into the overflow, y'know? Maybe practice pinching the tube so the suction is slow enough that the sand falls back out. For me, the gadgets are a poor substitute for husbandry, but not everyone vacs their sand so meh.

The thing is, you've got a lot of fish - that's a lot of food and poo. Understocked tanks seem to have it easier when it comes to balancing nutrient export and import. Overstocking makes more work. Sometimes gadgets are a lot of work too, you're cleaning out all those pads and filters and socks a couple times a week right?

All the coralline and no algae makes me think your water and rocks are pretty clean, even though you don't list any parameters. So I think the flow has kept everything from the sand up clean and pretty. But your sand got dirty as fish poop and old food landed on it. The water down there got a lot of nutrients in it as those things have decayed, and from sitting in it, the sand itself has absorbed some too. Now those nutrients are fertilizing algae and cyanobacter. None of the reactors and fuges and skimmers can clean water that doesn't reach them.

Thank you! I do clean the powerhead pads every time I do a water change, usually once a week. I think you are right though, the powerheads are quite high. I will put them further down to see how that goes. I think I don't have much chance in waiting for the sand to clean up by itself. It seems that the upper layer has absorbed enough to cause trouble. The plan is to lower the powerheads and remove the upper layer during the next water change and hopefully that will help a bit. I'll do a water test tomorrow to see where I stand, I am guilty for not doing one for some time now. Will post the findings then. Cheers!