Mystery slime on rocks?

[cvonseggern]

Can anybody look at this (very bad, but best I can do right now) pic and tell me what this stuff on the rocks between the xenia is? It doesn't look like the cyano I've battled off and on since setting up the tank. Diatom bloom? It blows off the rocks fairly easily, but some always gets left behind.

Thanks,

Chris

[Richard]

Probably dinoflagellates.

In addition to the normal algae controll stuff (keeping water quality high) you might want to start dripping kalkwasser for all top off. Keeping your ph high will help get rid of it.

[cvonseggern]

Based on what I can find here and elsewhere, I think Richard's the grand prize winner. Sure looks like the photos and descriptions of dinoflagellates I can find.

Sounds like this stuff is a HUGE pain to get rid of. Here's my tentative plan:
1. Continue manual removal
2. Turn lights (2x250W MH) off for 24 hours, then turn back on with a reduced cycle
2. Start thawing food (home-mixed and frozen) in R/O to soak off phosphates
3. Boost alk and pH (pH is 7.8 or so during the day, which is probably part of the problem; alk is about 14 dKH, Ca is off the chart). This is tougher to do, as I haven't got room for a kalk reactor or even a top-off bucket anywhere behind/beneath the tank. Looks like it'll be manual dosing for now.

Any other suggestions?

Chris

[JimD]

Its really hard to tell from that pic what it is, a better pic would be nice, but, I had Dinos really bad at one time, what worked for me was, manual removal, installing a refugium, dripping kalk, raising the Ph to 8.6 and Alk to around 10Dkh. Took about two months or so to go away and havent seen it since.

[::pete::]

So basically good water quality ;)

[cvonseggern]

Only problem I can detect is low pH. 14 dKH isn't all that low an alk AFAIK, and I have zero detectable ammonia/nitrite/nitrate. I don't have a PO4 kit, but I run PhosBan continuously. Is there any way to test for silicate?

[Richard]

If your test kits are reading correctly then if your alk is at 14 dKH and your daytime ph is only reaching 7.8 then there is something wrong.

Probably excess co2 in your tank or very often excess co2 in the room which is fairly common this time of year. Aerate some water outside and see if the ph rises and that will tell you if co2 is the problem.

There are some uncommon chemistry problems that can keep ph low when alkalinity is high. Very uncommon but since you say your calcium is off the charts then maybe???

Try the co2 test first and see if the ph rises.

[GaryP]

3. Boost alk and pH (pH is 7.8 or so during the day, which is probably part of the problem; alk is about 14 dKH, Ca is off the chart).

I don't see how this is possible. You can't have both super high alkalinity and high calcium at the same time. If you did your tank would look like a North Dakota blizzard.

As Richard said, it would be pretty hard to have your alkalinity that high and pH at 7.8 too. I would suggest getting someone else to test your water with their kits to verify your test data.

[::pete::]

Its not impossible.

[bigdscobra]

Its not impossible.

:blink :P