Question about combining two smaller tanks to one tank

[fullmonti]

I had two small mixed reef tanks set, a 18" cube with sump and a 10 gallon tall with a sump. I needed to combine them into one tank for a move. The new tank is a 30 breeder with a nice sump grow out/frag setup. I used the skimmer from the 18" cube and the media from both as well as the water from the both old tanks to set up the new tank.

I figured there would be a bit of settling in but nothing like setting up a tank from scratch. It's been a few weeks now and most of the sps has colored up nicely, a couple are a bit pale, some of the lps look happy and some less so. Some of my blastos are really not happy and have started to recede. Very fine pale very long algae showed up early on and I thought that would pass pretty quickly but it has gotten worse.

My nitrate is zip and phosphate is 0.02 so would not have thought I would be having algae issues. I may have to much media so I have been feeding the fish and corals a good bit to try and get a least a little nitrate to see if that helped but then there's the algae.

So my question is, is combing tanks like this just like stating a new tank from scratch and the algae is just a new tank thing? Or could there be something else going on?

[Oldreeferman]

My first concern would be from cleaning & messing with the substrate if combining 2 DTs, that will mess with the tanks stability for a while.
Only way around that would be if both DTs were bare bottom etc.

[fullmonti]

One of the two old tanks had a sand bed the other was BB. The new tank is BB. I was very careful to not disturb the sand when I took the water from the old tank. I can see how no sand could have some effect just didn't think it could be this big a deal but maybe it is?

[fullmonti]

Any one else have similar issues when they moved livestock from an older tank to a new one, using the old water, media and skimmer?

[taillonjohn]

since you have to move, you have no choice. I would suggest to use as much as possible from existing set up, except the old sand. Either use new sand or bare bottom, but use old filter, 100% of the water if possible, everything. algae problem can be fixed later but trying to avoid a cycle is your main concern

[Oldreeferman]

Something else i was thinking about is there was no mention about lighting changes, which there may be due to a larger DT setup now. Are you using a different lighting setup?
If so it could be effecting SPS corals they get used to the lighting & shock easily if not started dim & worked up slowly depending on the species.

[fullmonti]

The new tank is about the same footprint as the two old tanks combined. Each of the old tanks had a Kessil, I'm using both of them on the new tank with a strip light led for a fill part of the day much like the old tanks had. I tried to get the local PAR meter to check the PAR but the owner of it lives pretty far from me so never could work it out.

[Oldreeferman]

Sounds like lighting is not an issue.

Only thing im noting is your mention of no nitrates, LPS do require some nitrates.
I have both members of Blastomussa in my tank the merletti & the Wellsi and both are now mother colonys that started out as a single head and i always maintained a min of 5ppm and as much flow as i could get without being excessive as they are delicate when inflated.
One other thing i also do is feed them once a week, they do MUCH better being fed then not in the long run ive noticed, and i do not feed un natural foods like pellets etc just frozen brine with amino acids & vitamins added.
I first defrost the brine then pour off the sea water then i add new clean sea water, the aminos & the vitamin drops, this way none of the initial defrosting funky water is added to my tank. The LPS REALLY love eating, they are real gluttons especially the larger Wellsi. Try feeding them, your DT is too polished to not be feeding them and they will slowly recede & starve on light only at worst & at best will simply stop growing new heads.
I have a friend who is pretty anal about his tanks params & he has many of the same corals i have yet his are not growing just surviving with a few receding sadly & beyond a difference in lighting ( he is using LED, im using T5HOs) he simply will not hand feed them just a sprinkle for the fish & i watched his stingy short broadcast fish feeding and none of the foods land on any LPS and its only flakes & pellets anyway which i do not recommend for LPS anyway soft natural foods are easy to digest for LPS.
He simply will not take any advice even when i show him pics from my tank and we both started at the same time when we setup, its like arguing Politics sigh.........
So if you have not then try feeding them once a week if your minerals are at NSW lvls its probably the issue and may have been all along just now showing issues, coincidence happens a lot with reef tank issues.

[Oldreeferman]

Ive added a pic of my Blastos so you can see how well they are doing being fed

[fullmonti]

The no nitrates and very low phosphate plus bad algae is the puzzle to me. I always have fed the corals. A couple weeks ago I took about half the media out thinking there was too much and was stripping too much out of the tank but then there is the algae. I have been feeding the fish and the corals even more in spite of the algae. I have always had chaeto on reverse light cycle and have a good size space in this sump too, plus some media because there is basically no rock in this system. Only thing I know to do at this point is keep on and hope this is a bit like starting a new tank and the algae will clear up before to awful long???

[Oldreeferman]

Can you test & show all the DT params? And has any necessary filters been serviced?
Mag
Cal
ALK
Nitrite
Nitrate
Ammonia
PH
Temp

And is your salt Reef salt and what quality water do you have access to such as RO etc.? Am asking since this info is not available in original post and its about all i can see left that might cause issues with algae.

[fullmonti]

I'll have to check the Cal & Mag, haven't checked them in a very long time because I Have been doing large enough water changes it has never needed any additional added. Alk 9 +or- 1/2 point, PH 8.4or5, temp77, Nitrate 0 and I don't test for Nitrite or Ammonia, don't even have the kits.

I Use ORDI water and Reef Crystals.

I cleaned the skimmer good 2-3 weeks before the change over. This tank is a growout/frag tank with pretty much no rock. It has a 6 line, small damsel fish and 4 Mollies I changed over to saltwater (they never stop working, better than having a tang). The sump has a good size ball of cheato tumbling with reef grow lights, night Ph is 8.3or4.

I'm not new to reef tanks my first reef was in 2005or6, had saltwater fish in the 60s when I was a kid living in Florida.

The whole thing just seems odd to me when i went to so much effort to make the change over as seamless as possible and then to have such algae, so little nutrients and some of the corals so unhappy, some just OK and others look great. Just seems odd, probably just have to slowly settle in much like a new tank?

[Oldreeferman]

Id definatly check the Mag & Cal soon as possible Reef crystals i also use & in the beginning on frags no prob however once my corals began growing into colonies even weekly water changes could not keep up with Mag, Cal & especially ALK.
These 3 are the main ones that do need checking at least once a month min.
If these have not been kept checked id be very surprised in a hard coral DT growing out that isnt off in params.
Coralline also soaks up minerals at a huge rate once it gets a foothold.

[fullmonti]

OK Cal i have two different kits one said 420 the other 400. Mag 1350

Let me better redefine my question. I'm pretty sure the corals that are unhappy are so because of the 0 Nitrates and 0.02 phosphate low levels, I understand that.

My question is HOW and or WHY can I or anyone have an algae problem with really low nutrients?

I'm thinking of starting a new thread with that question as the title.

[Oldreeferman]

Do you have a algae CUC of snails?
Without pics every answer you get is going to be a guessing game with no visual of how bad the situation really is or isn't TBH.
Some algae is normal and expected, every person has their limit on what is normal visually tho.
Have you considered trying a different nitrate test to be certain your nitrate test kit is good yet?
Very rare to see a DT with no nitrates unless its super starved & super water polished.

[fullmonti]

I started another thread about this
http://reefcentral.com/forums/showthread.php?t=2712843

Check it for more info, some good info too