Question For the WWM Team. SPS RTN and Diatom growth... cause/s? Allowance/s?   6/11/08
Dear WWM Staff,
<Justin>
Your website has been a great resource too me and would like to thank you for your contribution to the hobby through this website, it is invaluable.
<Glad you find it useful>
I started in the hobby one and a half ago with a 12 gallon nano that was very successful. Six months into it I did my research and upgraded to a 70 gallon system. My current system setup is as follows:
Equipment
50g Clear for life pentagon corner acrylic tank with a back corner overflow box. The top front corners are drilled for the two returns, which is powered buy an in sump Eheim 1260 generating a 10x. I installed a closed loop by drilled the bottom right hand side of the tank for intake and the bottom right for the split returns. (see attached illustration 1).
<None of these came through. Must be attached...>
An external Poseidon PS3, generating an estimated 18x turnover, powers the closed loop creating a circular closed loop flow. I run a VorTech pump in an opposite position to the closed loop at half speed in reef crest mode creating turbulence and an additional 35x. I have a JBJ 1/10th Titanium chiller running in the well ventilated attic directly above the tank that is powered by an external Poseidon PS1, generating an estimated 8x turnover, and returns to the main tank. The lighting is a PFO mini pendant 250 MH running a 14,000K phoenix bulb, replaced last month. I run a 24” 65W, retro fit SunPaq PC actinic bulb and a set of two Current USA moon lights. I recently switched from an ASM G1 skimmer to a Tunze 9010. My sump is a custom built 20 gallon with a built in 3g refuge where I keep 5 lbs of miracle mud and Chaeto under a low watt bulb 24/7.
<Stop! I would not have the lighting on continuously here. Chaetomorpha needs a dark phase... I'd arrange the light to overlap, be on when the main display lighting is cycled off>
The overflow splits into two where 75% of the flow ends up in the skimmer side of the sump and 25% ends up in the refuge. I run a PhosBan reactor with Eco-Phos connected to a Maxijet 400 that pulls from the skimmer side of the sump and returns to the return side of the sump. I do not run a heater as the house is maintained at 74º and in combination with the MH I have been very successful in maintaining a stable temp of 77º.
Current Parameters – Very stable.
Temp 77º
Salinity 1.025
pH 8.3
Calcium 450
Alkalinity 10
Magnesium 1350
Nitrates 0
Nitrites 0
Phosphates 0
<Mmm... I'd read a bit re the need for soluble phosphate... your system, with the reactor, may be too "clean" for the livestock's good>
Ammonia 0
Maintenance Schedule
I change 10% weekly using Reef Crystals, but recently switched to
Reefer’s Best.
<The ZEOvit product>
All sponges are removed from the skimmer, pumps, PhosBan reactors and cleaned out, to ensure no phosphate built up. I dose B-Ionic and or DT’s new CA/Alk/Mag chemical additives. I dose a little Potassium (explanation later on) and Eco-Systems trace minerals. I run carbon for 5 days a month. I test all water parameters every Sunday at 8pm using Salifert test kits.
Feeding Schedule
I feed sparingly once a day and or every other day. I feed with Rod’s Food (http://www.rodsfood.com/).
Bio Load
1 Med. Yellow Tang
1 Dusky Jaw
1 Blue Chromis
2 small Clown fish
1 Royal Blue Tang
1 Small Six-line Wrasse
1 Peppermint Shrimp
1 Emerald crab
Large cleanup crew (no stars), snails, (Hawaiian Trochus Grazers, Hawaiian Turbo Grazer, Micro Hermits, Blue hermits, Strombus Grazers conch, ninja, Pinky Cuke, Hawaiian Littorinid Grazers, Astraea, Nassarius)
Natural Filtration
I have about 50 lbs of live rock and 30lbs of live sand.
Light Cycle
Moonlights off 7am
Actinic on 11am
MH on noon
MH off 9 pm
Actinic off 10 pm
Moonlights on 11pm
Issues
I have two ongoing issues that I cannot seem to resolve.
1) Diatoms – (one year later)
2) SPS RTN/STN
<This both may well be due to the lack/absence of HP04...>
I went through a very patient cycle and waited and waited. However I still to this day suffer from Diatoms. I have done everything listed on WWM site and more I have done two days of darkness, however they always return and are very prominent on the sand bed. They are densest by my Dusky Jaw, as assume it’s because the snails get used in the construction of his burrow and hence they stay away from him and the sand does not get mixed up in that area, however the rest of tank still suffers from bad diatom blooms.
I can keep pink and green Birdsnest that grow thick branches and have wonderful plop extension and color. However, I cannot keep any other SPS. Monti’s die by STN/RTN within weeks and never show signs of growth. I started adding potassium as the ZEOvit system promotes it and I had run out of options. I acclimate slowly via the drip method and place the coral low in the tank and slowly raise up towards the light as to not light shock the coral. All other forms of corals start to loose their tissue and then the diatoms start to attach and I inevitably loose the coral. (See illustration 2)
I have recently increased the weekly water changes to 15% and switched salts from reef crystals to Reefer’s Best to address the low potassium issue as tested by a ZEOvit user.
<K presence/concentration is rarely a rate limiting factor>
Other Info
The only piece of equipment that I did not buy new was the tank and it was used as a freshwater system.
My build thread on sdreefs : http://www.sdreefs.com/forums/showthread.php?t=25429&highlight=50g+build
Illustration 1
Illustration 2
Illustration 3
<Again, these graphics didn't make it>
Kind regards,
--
Justin A. Hai
<I'd pull the Phosban out... run this system for a few weeks... see what happens. Bob Fenner>