I reported somewhere else on forum that I had some green water in my QT pond. Used the Tetra product to clear green water but the green is slowly returning. Today I took the UV tube out only to find it cracked.

I have two concerns:

1 They state that the flow can only be 370L/h. This does not seem to be correct !!!! Must I replace my 50mm pvc pipe with valve with a straw to get that slow flow rate???

2 This unit contains a quartz crystal sleeve to hose the UV light. Does this mean that there is no direct contact between tube and water? The reason I am asking is that the tube was submersed in water when I took it out.

Manufacturer : Boyu
Product Model : UVC-20

Specification :
Volt - AC230/115V
Freq - 50/60Hz
Power - 20W
Flow - 370L/h
Size - 705x120x160mm
Features :
• Use uv-c quartz glass tube, high transmissivity of ultraviolet ray.
• Special ultraviolet bulb, perfect bacterium killing function.
• No chemical pollution to the environment.

Hi Maruis
The ultrazap UV or professional Quarts UV also has a specified flow rate, but the flow rate on your Boyu is very low, I have no experience with the Boyu UV.

The normal practice when you are going to exceed the specified flow rate, is to split the flow that will pass through the UV, and the rest to bypass direct to pond.

I use an 18000lt pump on the Professional quartz 55W UV without the need to split the water flow.

Yes no water contact between UV and water when using a quartz, which means your quartz tube is damaged to allow waster trough onto the UV. You will need to replace the quartz glass tube as well, before installing a new UV tube.

Thanks Bobby

Yes, it is heading for the bust bin today. I will rather stick to the Ultrazap as on my big pond. No problems at all to find spares for it and they use standard tubes

Marius, just a side note. Tubes usually do not crack or break while in the unit. So either the unit took a knock or....the lamp was on without water in the unit and when water came into the unit the sudden change in temperature caused it to crack.

2 Years ago I once took my old globe out to replace it. As i placed it into the new once packaging to throw away the old tube suddenly hissed and "exploded". Luckily it was in the new tubes packaging otherwise there would have been splinters everywhere. This has only happened once so far.

The lamp in a quarts unit never comes into contact with water, so I assume being on should no be a problem.
I agree a knock could have damaged the quarts tube, therefore the leak onto the UV

You will also find a rubber seal on both ends of the quarts tube, that could possibly leak water onto the UV tube.

It was hopelessly too small anyway. So just get the proper size from Ultra Zap and you will be fine. For real protection you should buy something double the size you need and only switch it on when needed.

bobby wrote:

The lamp in a quarts unit never comes into contact with water, so I assume being on should no be a problem.
I agree a knock could have damaged the quarts tube, therefore the leak onto the UV

Maar sal die quartz nie warm raak nie en ook bars nie... weet nie, ek raai maar net.

Neville wrote:

It was hopelessly too small anyway. So just get the proper size from Ultra Zap and you will be fine. For real protection you should buy something double the size you need and only switch it on when needed.

Hiemee stem ek saam. My groot dam het 3 x 55W ligte in en dit het min of meer 'n week geneem voordat water skoon was. Die 20W vir QT is veronderstel om genoegsaam te wees vir 7000L water maar hierdie produk is nie sy geld werd nie. Kos meer as die 55W Ultazap en gebruik 'n spesiale lamp. Die 20W unit is amper so groot soos die 55W Ultrazap en die 'sleeve' kan nie verwyder word nie ( lyk my dit vorm deel van die omhulsel)

Paar maande gelede toe ek die eenheid gekoop het was dit al wat beskikbaar was. Plaas ek eerder 2 dae gewag het en iets beters op internet bestel het.

My pomp het gebreek die dag voordat ek grow en show gekry het en dam het vir paar uur gestaan sonder water vloei. Dalk het lig toe seer gekry alhoewel ek die lig onder die watervlak geplaas het en kan dus nie droog loop nie.

Moet dalk byvoeg dat die pomp ook 'n Boy-u pomp was. Werk net totdat dit klaar betaal is

Hi Maruis for info
Ultrazap het ook 'n Professional Quarts model, bietjie duurder maar werk baie goed. Baie nice om UV tube te vervang, haal elektriesie koneksies af, trek uit tube sonder om water af te sit en vervang.
Dit kos ongeveer R300.00 rand om 'n 55w quarts buis te vervang, een van myne het vanaf 'n tafel geval.
Die wand van die quarts is redelik dik met 2 seals op die einde, maar nou ja dis nog steeds glas.

My vriend Chsitie se gister vir my dat daai Boyu UV's is einlik vir vis tenke bedoel. Blykbaar is die konneksie an die UV groot maar intern is die pypies om die gloei lamp baie klein.

Ek gebruik 'n SP 10 000 Boyu pomp op my Qt. Hy hardloop nou al vir 2.5 jaar en so ver niks probleme nie. Baie happy met hom.

[quote="wayneb"]My vriend Chsitie se gister vir my dat daai Boyu UV's is einlik vir vis tenke bedoel. Blykbaar is die konneksie an die UV groot maar intern is die pypies om die gloei lamp baie klein.quote]

Ek stem saam met dit wat Christie jou meegedeel het. Kyk bietjie hierna Dit is 'n stompie wat ek langs sleeve ingeduk het( seker so 7mm spasie aan kante en geen spasie aan die bo kant vir water nie)