Problems with Diatoms and Cyano

[thrlride]

Problem with Cyano and Diatoms
Here's my story:

History
I set my 29 up in May of 2003 and it started like every normal tank does. Got all the blooms and then everything stabalized. In the June of 2003 I started fighting Cyano. I used chemiclean and it helped but I'd rather fight the problem than an easy fix. I started doing more water changes using my RO/DI with Instant Ocean salt. I was still fighting it. I cut down feedings to twice a week and was still fighting it. Then, instead of just stirring the sand to bury the Cyano I started sucking it out using a tube and creating a syphon. It went away quickly when I did this.

Present
I moved my tank to a different house in September and since then I have been fighting Diatoms and Cyano again. I used new sand but reused all the 40 or so pounds of live rock I have. I do 20% weekly water changes, still feed twice a week and suck the sand with the syphon regularly. The TDS of my RO/DI is 0 and I am still using Instant Ocean salt. I did some water tests yesterday and here are my parms:

Amm - 0
Nitri - 0
Nitra - 0
PH - 8.0
SG - 1.025
Calcium - 300
Alk - 5.8 dkh
PO4 - .1

I was shocked to see the Calcium and Alk so low so now I am dosing part 1 and part 2 calcium/alk, hopefully to bring that up soon. Corals and fish are doing well except for some Xenia I got from someone a few days ago. It hasn't recovered from the 20 minute trip yet.

Lighting
I am using a 65 watt 50/50 PC bulb and a 55 watt Actinic PC bulb over the tank. The 50/50 bulb is over a year old but the Actinic is only a month old. I have read that an old bulb can cause diatoms because of the spectrum shift then I read a report that said that it is phsically impossible for a PC type bulb to have a spectrum shift... My light cycle is:

9:30 - 2245 Actinic
10:30 - 21:30 50/50

For circulation I have a MJ900 (230 gph) and a micro jet 450 (117 gph) along with the 250 gallons per hour the eclipse pump runs.
I run carbon but no bio-wheel. I don't dose anything except the part1/part2 I just started this morning. I do not add phytoplankton and I feed formula 1 flake or formula 1 frozen. When I do feed it is only a small pinch. My tank inhabitants are two percula clowns, a black/white damsel and a royal gramma along with a cleaner shrimp and snails/hermit crabs.

I know some answers are going to be get a fuge, get a skimmer...
The eclipse hood prevents this and within 6 or so months the 29 will be dismantled anyway to make room for a 90 that I am working on. The tank was fine without the skimmer and fuge before I moved, so I believe the moving was key to this problem.

Sorry for the long post but if you could help, please do.

[Anthony Calfo]

this is wholly about nutrient control and nutrient export, my friend.

Please do check in the archives for this and other good sites for an address of this issue at very great length.

The short story from me though is increase water flow (volume and/or direction) to keep solids in suspension for processing by filter-feeders and/or skimmer(s)... and get yourself a very good and friendly skimmer. Euro-reef style and Aqua C get high marks from me.

Also mentionable... your Calcium and Alkalinity balance is just jacked. Waaaaay off base here my friend. Simply do a series of large water changes with an even keeled salt like Tropic Marin to dilute the imbalance. And only then resume supplementing while using your test kits to determine a range. You must discover your daily demand for Ca (by testing) and how much of a given supplement is required to fill that daily demand (by testing). After that you can relax a while on testing :p

Anthony :)

[thrlride]

Thank you Anthony. I will increase the flow to the tank but am going to hold off on the skimmer since this tank will be replaced in a few months with a 90 that will have an ASM skimmer.
About the salt, figures, I just bought a 160 gallon tub of instant ocean. I may be able to sell it to a local reefer and buy some tropic marin.

Thank you for the advice.

[Anthony Calfo]

actually... no worries on the salt. I do like IO just fine/well enough. I just prefer Tropic Marin when available.

[thrlride]

I tested my water again the night before last and last night. Here are the results:

11/7/2004
Calcium - 330
Alk - 8.0

So I dosed just calcium

11/8/2004
Calcium - 340
Alk - 6.0

So I did part A and B again. I'm thinking the dose of calcium brought down the alk. It looks like the numbers are in a closer relationship now to where they are supposed to when they are 400+ and 8.0+. Is this true?

[Anthony Calfo]

I'm thinking your best bet is to do a large water change to get things back on even keel... then resume with balanced 2-part dosing. The Alk is still remarkably flat, and rather than see you go through the typical see-saw ride of adding buffer, then Ca, then buffer, etc... the large water change is best: "Dilution is the solution to pollution." :D

[thrlride]

Just for grins I checked my ro/di water with IO salt and it was 340 calcium and 8.0 dkh. Is that typical of IO?

I may not have mentioned this but I am using Salifert test kits.

[Anthony Calfo]

levels seem fairly "normal" and frankly just fine, although I'm wondering if the source water (RO) is being aerated and buffered adequately in advance of salting... else that is a burden indeed on the salt (few if any are formulated for use with RO water - all presume some mineral hardness in support). The pH could be a lot better for it.

[thrlride]

Well, this house is on a water softener. I'm not sure if the source from where I get the water is from the softener though. Could that have an effect?

BTW, thanks for all your help!

[Anthony Calfo]

a huge impact, my friend... you need to know the quality of the water you are using for evap or salt mixing. Only then can you prepare to make adequately buffered/stable water for use. This cold be a reason why things are flat. Do test your raw source/tap water for pH, Alk, etc.

[thrlride]

Raw, meaning before the RO/DI, correct?

[Anthony Calfo]

my fault... I meant to simply say "source water" - whatever the final water you are using is before evap or salting.

Hoping you remineralize/buffer/aerate before using always. You will see the difference if so. :)

[thrlride]

I usually make the water then add the salt to the proper amount. I have a MJ900 in there for areation. Do I need to do something else?

I will test that water tonight though.

[Anthony Calfo]

most sea salt is not manufactured for RO/DI use (they presume an average mineral hardness for support from the tap water). You need to remineralize it (and aerate ideally) before you do anything with it. It really does help IMO

[stevedola]

would his alk be flat because he added just calcium of the 2 part additive?> I remember that you cant simply add one part of the 2 part system with out skewing other results (ie alk).

[thrlride]

The calcium I added was just a straight calcium, it wasn't part of the two part system. Though that is a good question. I just read an article that said alk should not fall when calcium goes up. For some reason I thought they were on a balanced system, meaning when calcium went up alk went down unless you dosed both. LOL, now I don't know why my alk when down when adding calcium. I will test again to see where it is at now.