RO, RO/DI, or tap?

[charlypooh]

I've got a strange situation going on. I recently stopped using tap water for top offs and water changes (I know...smack upside the head for me...but my tap water has consistently tested within all parameters) and am now using RO water. Now, about two months after the changeover, I'm suddenly seeing diatoms and red slime algae that I haven't had an issue with in almost three years. I have added corals, but my fish bio load is reduced compared to just prior to the switch, so all should be pretty even with all items traded out.

Could the diatoms and algae be directly caused by the switch to RO? I remember reading something once regarding RO/DI being better than RO, and both being way better than tap as far as injecting phosphates and nitrates into the system, and seeing some comments that RO can cause algae blooms, but was wondering if anyone out there knows if there is any truth to that?
CJ

 

[Peppie]

I hate it when you upgrade thinking you are doing a better thing for your critters, and BAM it bites you in the ....
Sorry I dont have the correct answer
Have you tested the RO water with a TDS?
Is there anything else you have changed in your maintenance? Maybe a filter pad? Feeding more? Lights bulbs need changed?
I am just throwing some stuff out there.
It would help us if you could post your water parm. And a little more info on your system. Skimmer? Flow? Sump? Reactors? Lights?

 

[Shane and John]

Ro/DI is honestly the only thing that has worked well for us..In my oppinion.a rodi unit is the single most important part of keeping a successful reef..

 

[charlypooh]

No other changes other than gradual change from FOWLR to reef.

Tank is 46 gallon with CPR BakPak skimmer (no bio-bale), chiller, CPR Aquafuge2 (small size, containing sand, chaeto, a couple of small live rock chunks, and two pencil urchins), and Fluval G6 filtration unit running carbon and the fine mech filter (all bio media removed, i.e. empty baskets). The mech filter cartridge is cleaned at least weekly, and the G6 itself is cleaned monthly to remove any detritus which isn't much... The skimmer body is also completely cleaned monthly, or as needed for detritus buildup. I've gone with this setup mainly because I have no space for a sump setup undertank (haven't found one that's skinny enough but not too long). Lighting is a 250 watt MH with two 96 watt PCs on either side sitting about 6" above water level with the glass hood between. Lights are on day/night cycle timer and the photoperiod is currently set at 10 hours. The fuge light runs opposite the MH/PC. In all, the whole setup rounds out to about 50 gallons. Fish-wise, the tank contains a pair of oscellaris clowns, one coral beauty angel, and a jawfish. Other than that, there are snails and corals.

My last water parameters were (6/22, 24 hours after a 20% water change):
Temp - 77
Salinity - 51 ec/ms (approx. 1.024-1.025)
PH - 8.2
CA - 480
dKh - 13
Nitrite - 0
Nitrate - 30
Phosphate - .5
Ammonia - 0

I am planning on testing all paramaters again tonight. The one parameter that's been difficult to get under control during the conversion is the Nitrates. They bounce around for what seems like no reason. Prior to the 6/22 water change, Nitrates were sitting between 10 and 20ppm. I'm seeing a definite trend of them being higher after the water change which I expect after a mild sand stir, but I'm having trouble pinning them down and keeping them down. Prior to the change from tap water to RO (and FOWLR to reef), both nitrates and phosphates were consistently much higher than where they're at now, and I didn't have a red slime or diatom issue...

 

[charlypooh]

Oops...missed flow there. I've currently got two Koralias (a 2 and 3 if i remember correctly) which are positioned to intersect mid-front and flow coming from the G6 which varies depending on the condition of the mech cartridge.

TDS meter is on the to-get list, but I do not have one at the moment.

 

[Peppie]

Thanks for the info. Again I do not have a reply you need to hear, but with this info someone here will be better able to give information on your situation.
If it were my tank I would turn off my lights for three days. Then I would reduce the time my lights were on during the day by at least 2 hours.
I may be off base but it would help reduce the algae bloom untill you figure out what is causing it.

 

[IPisces]

Are they diatoms or dinoflagellates. In my small tank, I had dinoflagallets and red slime. Your nitrate and phosphate levels may be contributing to the outbreak.
I too would turn the lights out for a few days. Suction out as much of the algae you can now and a good water change after a few days.
Here is some info on dinoflagellates.

Problem Dinoflagellates and pH by Randy Holmes-Farley - Reefkeeping.com

 

[charlypooh]

Thank you IPisces. I took a look at the site you suggested, and don't think the brownish dusting on things match dinoflagellates. The article mentioned oxygen bubbles in "goo" and I definitely don't have that issue. It also mentioned that snails are intolerant, and mine are all cruising around the tank normally.

The only thing other than the brown-red hue the tank has taken on that's different is that the bristleworm population is suddenly not minding the light...I just about this while watching the tank a few ago, and figured it might be worth mention. Yesterday and today, I've been seeing them out in the light pretty regularly...even when I haven't fed. Normally, there's not a ton of uneaten food in the tank because I feed sparingly once a day with pellets and one or two days a week will feed one small cube of frozen mysis. So, with no change in feedings, it strikes me as odd that the worms are suddenly being so bold.

I think I'll give a try to reducing the photoperiod as suggested and see how things react.

 

[akunochi]

It will be easy to tell if it is dino or cyano. Is it gone at night and back throughout your photoperiod?

Your lghts are on way to long. 10 hours is far longer than any coral can chemically use the light. In fact you a probably going to stunt the growth if not outright bleach them.

Because you have a fuge with macro your phosphates test will be off as well as nitrates as both of these are used by tue macro to grow. All you are testing is what's left over after your macro is full.

How old are your bulbs and what color temp. Also pc bulbs swtch spectrum drastically and quickly.

Unless your rodi unit has exhausted filters it is not the cause of your problems.

 

[IPisces]

don't think the brownish dusting on things match dinoflagellates. The article mentioned oxygen bubbles in "goo" and I definitely don't have that issue. It also mentioned that snails are intolerant, and mine are all cruising around the tank normally.

This is good, cuase they are a pain to get rid of.

Are you making the RO water or are you getting it somewhere else.
Either way, get a portable tds meter and check it. And if your making it, invest in an extra canister and DI Resin and add it to your RO system. There must be excess nutrients somewhere. You might think about upping your flow. I have 2 koralia 1400's in my 50.

 

[charlypooh]

Your lghts are on way to long. 10 hours is far longer than any coral can chemically use the light. In fact you a probably going to stunt the growth if not outright bleach them. How old are your bulbs and what color temp. Also pc bulbs swtch spectrum drastically and quickly.

lighting is a mix...the mh is 10,000k, and is due for replacement. the pcs are both different. up front is a new 50/50 daylight/actinic 420nm and the rear is just actinic 420nm. as far as photo period goes, what suggestions are there on time? i'm definitely open to reducing it and lowering my electric bill a bit...

most of what i've seen when reading about lighting is that average is about 8-10 hours of mh with about 2 hours of supplemental lighting on either side of that time period. it seems like nobody out there really agrees on what's best where lighting is concerned... with the current lighting, the corals have actually been growing very well, there were one or two that were lost within days of adding them, but everything else in there is showing new polyps, increased size, and no signs of bleaching or die-off. maybe the key to that is that i don't have anything placed higher than mid-tank?